Interdisciplinary Behavioral and Social Science Research

IBSS Interdisciplinary Team Exploratory Project:



The Globalization of Empires and Cities since 1500 BCE

Artist’s conception of the Cothon, the military harbor of Carthage


PI: Christopher Chase-Dunn (Sociology and IROWS, UCR)

Co-PI: Eugene Anderson (Anthropology, UCR) 

Co-PI: David Wilkinson (Political Science, UCLA) 

Draft 11-30-15; 12553 words

Project Calendar Schedule: Submitted to NSF: December 1, 2015; Start date:  July 1, 2016; End date:  June 30, 2018; Duration: 30 months. Indirect cost rate= 52%.



This exploratory project will construct a multidisciplinary theoretical research program and test hypotheses about the causes of changes in city and empire sizes from the second millennium BCE to the present in order to shed light on the contemporary and near future global situation.  The Settlements and Polities (SETPOL) project will inventory explanations of scale changes from anthropology, sociology and political science and will develop and populate templates for a graph database that will allow the use of  geographical and network analyses for studying interactions among cities and empires. This database structure will make it possible to test causal propositions and models derived from the comparative evolutionary world-systems perspective, geopolitics, and human ecology -- theoretical perspectives that have been developed by sociologists, anthropologists and political scientists--to construct a multidisciplinary sociohistorical theoretical research program. The quantitative graph database will include the territorial sizes of states and empires (polities), the population sizes of cities and polities, interaction links and climate change in ten world regions over the past 3500 years. The project will also spatially bound whole interaction networks by estimating changes in the boundaries and intensities of human interactions of several kinds: everyday necessities, the trade of high value goods, the interactions of fighting and allying polities and the diffusion of ideas and genetic materials. SETPOL will code the power configurations (unipolar, bipolar, multipolar, etc.) of interstate systems and the world-system positions of settlements and polities (core, semiperiphery and periphery) within regional interaction networks. Causal propositions will be tested using five different units of analysis: individual cities and polities, networks of interacting cities and polities and spatially constant regions and the whole Earth as a single context for studying the causes of changes in urban and polity scales. A research team from archaeology, anthropology, geography, history, political science, sociology, ecology and climatology will carry out this first two-year phase. The multidisciplinary theoretical research program that will be developed will come primarily from anthropology, sociology, political science and geography, but participation by climatologists, historians, computer scientists and ecologists will contribute to the production of an improved database that allows for the use of geographical and network research methods. 

Intellectual Merit

The long-standing upward trends in the sizes of cities and polities is well known, but still in dispute are the long-term, proximate and contextual causes of these trends. The SETPOL project will improve upon, and extend, existing quantitative compilations of estimates of the sizes of cities and polities to identify those instances in ten world regions in which upsweeps in polity and city sizes have occurred, and will empirically examine the human and natural factors that have been hypothesized to be the causes of these instances of scale change. The project will also identify instances of collapse in the sizes of polities and cities and will study their causes. The project will develop best approximations of the growth and intensity of interaction networks that have constituted economic and political globalization since the late Bronze Age. The project will employ both standard comparative methods and recently developed geographical and network approaches to data analysis that use both GIS spatial analysis and formal network methods. This will contribute to the scientific understanding of the causes of the emergence of complexity and hierarchy in human societies and will deepen the understanding of sociocultural evolutionary processes.

Broader Impacts

Scientifically formulated and tested explanations of the development of complexity and hierarchy in human societies will help scholars, educators and policy-makers to better understand the patterns of historical sociocultural evolution and their implications for the future of humankind. The project will also allow us to provide fresh evidence on the comparisons of similarities and differences across world regions with important implications for explanations of uneven East/West development – issues that have been totemic and fundamental in the development of social sciences since the eighteenth century. The results of this research will have important implications for issues such as societal responses to climate change, ecological degradation, population density, the changing nature of the global city system, the rise and fall of hegemonic core powers, transitions from unipolar to multipolar power situations, as well as resilience and systemic collapse.  The SETPOL project will make its standardized geospatial data set publicly available and will coordinate and collaborate with other world historical data consortia. Participants in the project will develop undergraduate and graduate level courses and research projects to train students to do multidisciplinary research and to develop creative infographic presentations for classroom and general educational use.

Project Description

The Settlements and Polities (SETPOL) project will use both quantitative estimates of population sizes of the largest cities in world regions and estimates of the territorial sizes of largest states and empires to study the causes of changes in the scale of human institutions. Upsweeps are instances in which the largest settlement[1] or polity in a region significantly increases in size for the first time. The project will use world regions and whole interaction networks (world-systems) as well as single polities and cities as units of analysis.[2] This proposed multidisciplinary research is organized around the territorial sizes of polities[3] and the population sizes of cities because these are relatively easily ascertainable quantitative indicators of system size and complexity. Interval scale metrics are needed in order to tell the difference between small and large changes in scale.  When human sociocultural systems are studied over long periods of time cyclical processes of population growth and decline, the rise and fall of large and strong polities, are empirically evident. This project will employ a systematic method[4] of differentiating between a “normal” upswing or downswing in which the scale of sociocultural organization is fluctuating around an equilibrium level and an event of growth or decline that is significantly greater than the normal fluctuations (see Figure 1).  Focusing on the largest cities and polities in each region rather than on individual cities or polities makes these cycles of upswings, downswings, upsweeps and collapses visible.  Are the forces and conditions that cause upsweeps simply larger than those that cause upswings, or are different factors involved? Or do they combine in different ways? And are the causes of upsweeps the same as the causes of collapses but in reverse? The project will use upswings, upsweeps, downswings, downsweeps and collapses of city and polity sizes as dependent variables to be explained. This project will study city and polity sizes in ten world regions from 1500 BCE until 2010 CE.

Figure 1. Types of Medium-term Scale Change in the Largest Cities and Polities


SETPOL will use several different entities as foci of data collection and as units of analysis:

SETPOL will build on and improve earlier data compendia and will use the upgraded data to more accurately identify upsweep and collapse events (Inoue et al 2012 and Inoue et al 2015).  An example of results obtained using the territorial sizes of the largest polities in Europe and East Asia is shown in Figure 2.

Figure 2: Sizes of largest polities in Europe and East Asia (square megameters): 1500 BCE- 2010CE


            This figure shows the sizes of the largest states and empires in Europe and East Asia since 1500 BCE. Both regions show the overall long-term trend toward greater polity sizes and also the sequences of shorter-term fluctuations. When we look at Europe’s trajectory vis a vis East Asia in Figure 2 we can see that the rise of the Han Empire in China began earlier than the rise of the large Macedonian and Roman empires in Europe and the decline began earlier in East Asia than it did in Europe. China did it first, followed not long after by Europe. The European peak then last rather longer than did the Chinese peak. This was what many have observed as the unusually long tenure of the Roman Empire. Then Europe went into a long slump while Tang China recovered. So these waves of empire formation were partly, but not entirely, synchronous, and Walter Scheidel’s (2009) idea of the first great divergence[5] is supported, but the apparent divergence was partly due to the earlier start of East Asia. The later rise of Europe began in the 15th century, contrary to Andre Gunder Frank’s (1998,2014) contention that the great divergence that was the rise of Europe was a late and conjunctural event. Qing China also got larger but ended up only half as large as the British Empire.

            The main multidisciplinary theoretical thrust of SETPOL is based on a scope of comparison that comes from anthropology, archaeology and world history. This scope is combined with competing explanations of scale changes that come from ecology, sociology, history and political science, especially international relations theory.[6]  Sociology gave birth to the world-system perspective (Wallerstein 1974), which posits the existence of a hierarchical Europe-centered interstate system that emerged in the long sixteenth century CE[7] in which some polities (those in the core) exploit and dominate others (the semiperiphery and the periphery).  SETPOL will utilize an anthropological and world historical framework to compare small, regional and global world-systems over the past 3500 years (Chase-Dunn and Hall 1997; Chase-Dunn and Lerro 2014). .

Political scientists focus on political institutions and on international relations, especially regarding power dynamics among competing states, institutions of diplomacy and arms races. International relations theory focuses on geopolitics as a struggle for power in which military capabilities and warfare are central components. Geopolitics is most often understood as a multiplayer game in which territorial strategies are an important element, in means and ends, of power struggles. Most international relations theorists focus on the interstate system that emerged in Europe after being institutionally defined by the treaty of Westphalia in 1648 CE. SETPOL uses an anthropological and world historical framework to examine the nature of interstate systems since the emergence of early states in Mesopotamia and Egypt.

Chase-Dunn and Hall (1997) contend that world-systems, defined as interaction networks with consequential effects for local social structures, are the most important unit of analysis for explaining large-scale social change.  The evolutionary[8] world-systems perspective allows comparisons between whole interaction networks that are different in size, period and location.  They point out that different kinds of interaction have distinct spatial characteristics and degrees of importance in different kinds of world-systems. Chase-Dunn and Hall (1997) employ a place-centric approach that bounds spatial networks by asking what reproduces or changes the social structures of a designated locality. Always important are low value per unit of weight food and other everyday raw materials (bulk goods) that form a network that is usually spatially smaller than the network of political/military interaction. And there are even larger networks formed by exchanges of information and prestige goods that may be consequential for local social structures. Chase-Dunn and Hall (1997) also turn the issue of core/periphery hierarchies into an empirical question rather than a definitional assumption. The evolutionary comparative world-systems approach allows for the possibility that world-systems might exist that do not have core/periphery hierarchies, and indeed the small-scale system in indigenous Northern California studied by Chase-Dunn and Mann (1998) had very limited interpolity domination and exploitation. Core/periphery hierarchies emerge and evolve, along with other types of inequality, as the capabilities of some polities to extract resources from distant peoples develop.

Most state-based world-systems are organized as hierarchical interstate systems in which core polities and cities exploit and dominate non-core peoples. Power is organized in different ways in different systems and so what semiperipherality is in any system depends on what coreness and peripherality are. These are relational concepts. But it is possible to identify these world-system positions in very different kinds of systems based on common characteristics that are associated with them such as population density, geographical location, and differences in modes of accumulation (foraging, pastoralism, horticulture, agriculture, scale of irrigation, industrialization). Chase-Dunn and Hall (1997) describe a phenomenon they call “semiperipheral development.”  This involves the observation that peoples and polities that are semiperipheral vis a vis the larger world-system of which they are a part are more likely to implement technological and organizational forms that facilitate upward mobility and/or that change the developmental logic of world-systems.  One variety of this phenomenon involves semiperipheral marcher states that conquer older core regions to produce an upsweep in polity size. Another variety involves semiperipheral capitalist city-states that are agents of commodification—the expansion and deepening of trade networks. Increasing trade and production for exchange facilitates provides a fertile context for the emergence of larger cities and larger polities.

There are several possible processes that might account for the phenomenon of semiperipheral development. Randall Collins (1999) has argued that the phenomenon of marcher states conquering other states to make larger empires is due to the “marcher state advantage.” Being out on the edge of a core region of competing states allows more maneuverability because it is not necessary to defend the rear. This geopolitical advantage allows military resources to be concentrated on vulnerable neighbors. Peter Turchin (2003) has argued that the relevant process is one in which group solidarity is enhanced by being on a “metaethnic frontier” in which the clash of contending cultures produces strong cohesion and cooperation within a frontier polity, allowing it to perform great feats. Carroll Quigley (1961) distilled a somewhat similar theory from the works of Arnold Toynbee. Another factor affecting within-group solidarity is the different degrees of internal stratification usually found in premodern systems between the core and the semiperiphery. Core societies develop old, crusty and bloated elites who rely on mercenaries and “foreigners” as subalterns, while semiperipheral leaders are often charismatic individuals who identify with their soldiers and citizens (and vice versa). Less inequality within a polity often means greater group solidarity and this may be an important part of the semiperipheral advantage. Ibn Khaldun’s (1958) model of nomadic barbarians conquering decrepit old civilizations has been an inspiration to some of this thinking. And the tie with internal inequality may also be linked with waves of population growth and unrest within polities – the so-called “secular cycle” (Goldstone 1991; Turchin and Nefadov 2009). 

Hub theories of innovation have been popular among world historians (e.g. McNeill and McNeill 2003; Christian 2004) and human ecologists (Hawley 1950). These hold that new ideas and institutions emerge in central settlements where information crossroads are located. Mixing and recombination of ideas and information leads to the emergence of new formulations. Recent studies have shown evidence that information exchange, innovations, and political, economic and social activities increase exponentially with city size (Ortman et al. 2014; Ortman et al. 2015). 

            Esther Boserup (1965) developed a demographic theory that focuses on population growth and population pressure as the master variables behind social change. Technological change was explained as an adaptation to population density nearing or exceeding the carrying capacity of the environment under a given technological regime. Cultural ecology and population pressure have important implications for sociocultural development when they are combined with the idea of social and ecological circumscription proposed by Robert Carneiro (1978). Carneiro explained the social organizational ruptures that produced the first states in terms of population pressure in a geographic situation in which outmigration was impossible or very costly. Under these conditions people stay and fight rather than migrating. High levels of warfare killed off population and reduced population pressures. Some systems got caught in a vicious cycle in which warfare operated as a demographic regulator (e.g. Kirch 1991). But in other systems people became tired of warfare and allowed the emergence of elites who organized larger polities that regulated conflict and resource allocation (property). The elements of population pressure, intensification of production, ecological degradation, technological change, conflict, and circumscription are combined in different ways by different theorists, but these are the main ingredients that comprise most of the explanations of long run cultural evolution by archaeologists and many anthropologists (e.g., Johnson and Earle 1987; see also Chase-Dunn and Hall 1997: Chapter 6).

      SETPOL will test a large number of hypotheses because it employs multiple units of analysis and several kinds of network links. The main dependent variables will be changes in the scale of polities and cities. Individual polities and cities will be studied, and the sizes of the largest of these within regions and interaction networks will be studied as characteristics of the region or the network.[9] As mentioned above this project will divide the indicators of scale change into upswings, upsweeps, downswings, downsweeps, surges and collapses (Inoue et al 2012). Though these are all based on the sizes of largest cities and polities, timing and the way in which the unit of analysis is employed (regions vs different kinds of networks) will affect the identification of these scale changes. The main independent variables that will be studied are: the world-system positions of polities and cities (core-semiperiphery-periphery), the power configurations of interstate systems (unipolar, bipolar, multipolar, etc.) (Wilkinson 2003), changes in the intensity of warfare, network node centrality, the centralization of whole networks (graph centrality); climate change, and environmental degradation. The project will also examine the extent to which changes in the sizes of cities are associated with changes in the sizes polities. In addition to focusing on the largest cities or polities in each region or network, the project will also compute and study the size distributions of largest cities and polities. Urban geographers have long theorized about the causes and consequences of city size distributions.[10] Our comparison of largest polities in East Asia, Europe and the Central Political/Military Network[11] will enable us to ascertain how the size distributions have changed over time and how these may be related with scale changes and possible inter-regional synchronies.

Here are eleven examples of testable hypotheses generated by these independent and dependent variables:

1.       Upsweeps of polity and city sizes have been mainly caused by the phenomenon of semiperipheral development – marcher states or capitalist city-states  (world-systems theory)

2.       Settlements that have greater centrality in exchange networks are more likely to innovate and grow, causing upswings and upsweeps (hub theory)

3.       Environmental degradation causes collapses of cities and polities (Diamond 2005).

4.       Climate worsening (droughts, flooding) causes downswings and collapses (Lieberman 2003).

5.       Rapid climate worsening may cause adaptive responses that eventually lead to city and empire upsweeps (Fagan 2005).

6.       Innovations occur that occur at centrally located network nodes are important causes of polity and urban upsweeps.(node theory)

7.       City upswings and upsweeps are caused by polity upswings and upsweeps.

8.       When formerly disconnected regional networks become linked with one another, forming larger interaction networks, cycles of urban and polity growth become synchronized (Beaujard 2005, 2010; Lieberman 2009).

9.       It is in periods of relatively intense warfare that polity upsweeps occur (iteration model).

10.    Large empires originate from metaethnic frontiers in which cultures with different and conflicting values interact (Turchin 2003).

11.    Regions and networks with lognormal size distributions are more stable than those with flat or primate size distributions (urban geography).

The theoretical research program that will be produced by SETPOL will develop an integrated synthetic model of the long-term causes of human sociocultural evolution – specifically the growth of cities and polities, but also increasing structural complexity and hierarchy in human polities and world-systems. The first job will be a broad multidisciplinary inventory of theories and causal propositions, an expanded and elaborated version of Chase-Dunn and Inoue (2011). We will also develop our own theoretical model that integrates the iteration model produced by Chase-Dunn and Hall (1997: Chapter 6; Chase-Dunn and Lerro 2014: Figure 2.5 on page 27) with the structural demographic model developed by Jack Goldstone (1991) and elaborated and formalized by Peter Turchin and Sergey Nefadov (2009). The multilevel model will include processes that operate within settlements and polities, especially demographic growth, population pressure, growing inequalities, social movements and state failure, with processes that operate between polities (warfare, interpolity trade, semiperipheral development, etc.) and climate change and epidemic diseases.


A Comparative Framework

This section outlines our proposed comparative multidisciplinary framework for studying the causes of scale changes of city and polity sizes. SETPOL will study expanding and contracting interaction networks among human polities and settlements as both units of analysis and as causal contexts of scale changes in the sizes of cities and empires. Human interaction networks have expanded and intensified over the long run (globalization), but in the medium-run there have been cycles of network expansion and contraction.

The best way to spatially bound human social systems is an old question that continues to generate heated disputes among social scientists. Michael Mann (1986) notes that different important kinds of interaction have different spatial scales, and so the notion that societies have single spatial boundaries is usually incorrect and causes much misunderstanding. Many regionalists define regions in terms of homogenous attributes, either natural or social.  Comparative civilizationists have tended to focus on the core cultural characteristics that are embodied in religions or world-views and have constructed lists of such culturally defined civilizations that then become the “cases” for the study of social change (e.g. Melko and Leighton 1987). Another approach that defines regions as areas with homogenous characteristics is the “culture area” approach developed by Alfred L. Kroeber and his colleagues (e.g. Wissler 1927; Kroeber 1944). This project gathered valuable information on all sorts of cultural attributes such as languages, architectural styles, technologies of production, and kinship structures, and used these to designate bounded and adjacent “culture areas” that have been widely used to organize studies of indigenous peoples (e.g. Sturtevant 1978-2007, the Smithsonian Handbook of North American Indians).

A major problem with both the civilizationist and the cultural area traditions is the assumption that homogeneity is a good approach to bounding whole social systems. Heterogeneity rather than homogeneity has long been an important aspect of human social systems because different kinds of groups often complement one another and interaction often produces co-evolution and differentiation.[12] The effort to bound systems as homogeneous regions obscures this important fact. Spatial distributions of homogeneous characteristics do not bound separate social systems. Indeed, social heterogeneity is often produced by interaction, as in the cases of core/periphery differentiation, urban/rural, and sedentary/nomadic systems. Even sophisticated approaches that examine distributions of spatial characteristics statistically must make quite arbitrary choices in order to specify regional boundaries (Burton, Moore, Whiting and Romney 1996).

David Wilkinson (2003) has made a strong case for studying civilizations as networks of allying and fighting polities and he has produced a chronograph of the expansion of the interstate system that emerged when the Mesopotamian and Egyptian systems became linked around 1500 BCE (Wilkinson 1987). Many world-systems scholars have contended that trade networks are the best unit of analysis for spatially bounding whole systems (Abu-Lughod 1989; Beaujard 2005, 2010). Immanuel Wallerstein (1995; 2011 [1974]) contends that a hierarchical core/periphery division of labor, especially the one that emerged with Europe as its core in the long 16th century CE, is the best way to spatially bound a world-system. And several eminent scholars have claimed that there has been a single global (Earth-wide) system for millennia (Lenski 2005; Frank and Gills 1994; Modelski 2003; Modelski, Devezas and Thompson 2008, and Chew 2001, 2007). Our research project will operationalize all these units of analysis and will pit them against one another regarding their relevance for explaining scale changes of polities and cities. We are also convening a workshop to more completely and accurately specify the changes in trade and PMN network boundaries since 1500 BCE (Chase-Dunn et al 2015a). We also will use constant regions to make comparisons so that it is possible to compare the results with what we find when we use spatially-bounded networks.



Figure 3: Ten world regions for studying the emergence of large cities and polities


These boundaries have been chosen in order to facilitate the comparative study of the emergence of largest cities and polities over the past 3500 years. The regional boundaries shown are mainly matters of convenience. All cities and polities will be geocoded so that different regional configurations may be easily used by other researchers. These regions have been chosen so that we may construct a data compendium that will include information on all the areas of the Earth where humans have lived in large numbers. The regions chosen for Figure 3 are mainly based on our knowledge of where large cities and empires emerged in the period we are studying. But we have also considered the social science literature that has hypothesized comparisons and connections among regions in our designation of regions. We are well aware of the issue of Eurocentrism in social science and the obvious point that “Europe” is not a continent, but is rather a promontory of Eurasia (Lewis and Wigen 1997). Social science itself has been constructed around comparisons between East and West and so an important way to scientifically address the issues of comparison and connections is to use some of the categories that have been constructed in the past to see whether alleged differences (or similarities) are supported or contradicted  by quantitative data.

Admittedly some of the bounding decisions we have made are somewhat arbitrary. We included the Caribbean with South America rather than with North and Central America because migrants from South America mainly peopled it. We made a great effort to have only ten world regions rather than some larger number of regions in order to keep our data gathering structure from becoming too complicated. But it should be recalled that all of the settlements and polities we study will be geocoded, so if other researchers want to reconfigure regions in a different way it will be relatively easy.

Using world regions designated in this way will allow us to address the important issues raised by world historians and civilizationists who compare regions (e.g. Pomeranz 2000; Scheidel 2009, Wong 1997; Morris 2010, Frank 1998). The project will also be able to compare the use of these spatially constant regions with what we find when we use expanding networks (e.g. Chase-Dunn et al 2015b). The proposed operationalization of network boundaries will first compile a propositional inventory of statements by social scientists about when smaller networks expanded, merged and when larger networks engulfed smaller ones (e.g. Beaujard 2005; 2010; Wilkinson 1992a; 1992b 1993). Then the project will use data on trade networks, historical accounts of warfare and diplomacy and studies of the diffusion of plants, animals, and technologies and ideas to evaluate the claims made by scholars about interaction networks and the timing of their expansions. These proposed units of analysis are listed on pages 2 and 3 above.


Chronological Issues

For purposes of comparing the timing of changes in city and polity sizes across different world regions it is important to have accurate absolute chronologies for the regions being compared in order to examine issues of priority and synchrony. Unfortunately there is still considerable disagreement about the absolute dating for Mesopotamia before 1500 BCE. Mario Liverani (2014: 9-16) explains why estimates of absolute dates are so uncertain. Relative dates of events needed for estimating polity and city sizes are based on “king lists.” Thus an event, such as a conquest, is said to have occurred in the third year of the reign of King X. Considerable effort has been made to figure out the correspondences between different kings’ lists in Mesopotamia and their correspondence with Egyptian king lists, which are more continuous. These are then converted in to calendar years by ascertaining their relationships with astronomical events such as eclipses. Unfortunately there is a period after the fall of the Babylonian empire in which king lists are missing for Mesopotamia, and there is disagreement about the timing of astronomical events. Thus the length in years of the occluded period is in dispute, and this results in so-called, short, medium and long chronologies for the period before the Late Bronze Age, with an error of as much as 100 years. Absolute dating is needed in order to compare the timing of scale changes across world regions.  It matters whether or not the city of Ur was sacked in 2004 BCE, and thus is eliminated from the list of large cities and large polities in 2000 BCE, or in some other year 50 years earlier or later. Liverani (2014: 15) is satisfied to use the middle chronology for Mesopotamia and the surrounding regions, but he is not trying to compare the timing of changes in the Ancient Near East with other world regions. The second phase of the SETPOL project will also use the middle chronology, while being careful to determine which chronology has been used in the sources from which estimates are coded. And the project will be chary regarding temporal comparisons among regions before 1500 BCE.

            The SETPOL goal is to achieve a minimum temporal resolution of every twenty-five years because the project is studying middle-run growth/decline phases of polities and cities. Archaeological evidence of the areal sizes of settlements and hearth counts can be used to estimate settlement sizes, but the limitation here is often temporal resolution. Studies that rely on radiocarbon dating and archaeological phase periodization often do not achieve a level of temporal resolution that would make settlement growth/decline phases visible (e.g. Ortman, Cabaniss, Sturm and Bettancourt 2014). When temporal resolution is poorer than every 100 years it is likely that some of the cycles of growth and decline will be missed.  In the first phase of our project we will focus on regions for which both documentary and archaeological evidence are available, and since this phase begins with 1500 BCE we do not need to worry about the issue of absolute dates when comparing world regions.


Data Upgrading[13]  

Improving of estimates of the population sizes of settlements and the territorial sizes of polities is an endless task, but much has been accomplished. The long term intent of the SETPOL project is to include all the towns and cities with 10,0000 or more people and all the polities with .01 or larger square megameters of territory in the ten world regions from 4000 BCE to 2010 CE. But in the exploratory phase of the project (the first two years) the project will prioritize by focusing on upgrading existing data sets that include the ten largest cities and polities in each of the world regions at 25-year intervals since 1500 BCE. 


Improving estimates of the territorial sizes of polities

Determining scale shifts requires real metric (interval-level) estimates, not just periodizations of growth and decline. The territorial sizes of polities are difficult to estimate from archaeological evidence alone (see Smith and Montiel 2001). What the SETPOL project wants to know is the size of the area over which a central power exercises a degree of control that allows for the appropriation of important resources (taxes and tribute). The ability to extract resources falls off with distance from the center in all polities, and controlling larger and larger territories requires the invention of new transportation, communications and organizational technologies [what Michael Mann (1986) has called “techniques of power”]. Military technologies and bureaucracies are important institutional inventions that make possible the extraction of resources over great distances, but so are new ideologies and new technologies of communication (Innis 1950).[14]

            Estimating the territorial sizes of states and empires has been based on the use of published historical atlases and historical accounts. Premodern states and empires often had fuzzy boundaries. Bounding polities is based primarily on knowledge about who conquered which city, and whether or not, and for how long, tribute was paid to the conquering polity. Sometimes it is difficult to tell whether or not tribute is asymmetrical or symmetrical exchange. Only asymmetrical (unequal) exchange signifies a tributary imperial relationship. Otherwise it is just trade and does not signify an extractive relationship.

The pioneer coder of the territorial sizes of polities is Rein Taagepera (1978a, 1978b, 1979, and 1997). The SETPOL project builds upon Taagepera’s monumental work and uses his methods. Taagepera used Atlases and historical descriptions of events to estimate the territorial sizes of states and empires. This project will improve upon his estimates by using Atlases that had not been published when Taagepera did his work (e.g. Schwartzberg (1992). The project will also use online sources such as the University of Sydney Timemap Project. The values produced from these tertiary sources will be checked with regional experts (see Data Management section).The SETPOL polity data template utilizes Taagepera’s method of coding the year in which polity sizes change, usually as a result of conquests, and will designate area in square megameters as Taagepera did.[15] It will also include a standardized identification code for each separate polity, fields for alternative names of the polity, geocodes for the location of the capital city and estimates of the population size of the polity.[16]


Improving estimates of the population sizes of cities and territorial sizes of states and empires

            SETPOL is developing a template for coding characteristics of individual cities that include estimates of the size of the built up area as well as estimates of the population size. The city template also includes unique identifiers for each city, fields for alternative names of the city and the geocode of the city center.  For the location identification, the geo URI scheme is applied.[17]  The data are structured in the three dimensions—each city has sets of variables, and each of these variables has varying value ranges and time intervals. The variables and their definitions are being developed in collaboration with the SESHAT project team in order to avoid redundancies in collecting data. A template for polities for coding similar variables is also being constructed. 

Making accurate estimations of the population sizes of both contemporary and early urbanized areas involves several complicated problems. Daniel Pasciuti (Pasciuti 2003; Pasciuti and Chase-Dunn 2003) has proposed a measurement error model for estimating the sizes of settlements based on the literature in archaeology, demography and urban geography.[18] The SETPOL project defines a settlement as a spatially contiguous built-up area.[19] This is the best operationalization for comparing the sizes of settlements across different polities and cultures because it ignores the complicated issues of governance boundaries (e.g. municipal districts, etc). But it still has some problems. Most cultures have nucleated settlements in which residential areas surround a monumental, governmental or commercial center. In such cases it is fairly easy to spatially bound a contiguous built up area based on the declining spatial density of human constructions. But other cultures space residences out rather than concentrating them near a central place (e.g. many of the settlements in the prehistoric American Southwest such as Chaco Canyon).  In such cases it is necessary to choose a standard radius from the center in order to make comparisons of population sizes over time or across cultures.

Existing compilations of city sizes rely primarily on:

1.       Tertius Chandler 1987 Four Thousand Years of Urban Growth: The Edwin Mellen Press

2.       George Modelski 2003 World Cities: –3000 to 2000. Washington, DC:  Faros 2000

3.        Ian Morris 2013 The Measure of Civilization. Princeton, NJ: Princeton University Press.

Tertius Chandler’s (1987) compendium is still the most comprehensive study of large cities, but substantial improvements were made in George Modelski’s (2003) compendium. Ian Morris also provides estimates of the largest cities in his book on measuring the development of Eastern and Western civilizations (Morris 2013). The SETPOL project will improve upon existing city size compilations by collaborating with other projects and incorporating data sets produced by others.[20] The proposed city template includes both the calendar year in which the size of a city is known to have rapidly changed (e.g. the example of the sack of Ur mentioned above) as well as interpolated estimates for the standardized years used by Chandler and Modelski.[21]



The research and analysis will be conducted at the University of California-Riverside and at the University of California-Los Angeles.  The PI and the co-PIs will coordinate the project along with research associates at the Institute for Research on World-Systems. The project will be conducted with graduate students and advanced undergraduates who will work for pay or for course credit.  Weekly project meetings will be held in Riverside using online videoconferencing for those participants who are not in Riverside. Progress reports and research papers will be presented at annual meetings of the American Sociological Association, the International Studies Association, the Society for American Archaeology, the World Congress of Sociology and the Social Science History Association as well as at other professional meetings in the United States and abroad. 

Throughout the project intellectual cooperation will be sought from collaborators and consultants from several different disciplines. The following colleagues have indicated that they are willing to collaborate on this project:

·         Gullermo Algaze (Archaeology, University of California-San Diego, Regional Focus: Southwest Asia)

·         Robert J. Allen (Earth Sciences, University of California-Riverside)

·         Philippe Beaujard (History, Université Paris 1-CEMAF, Regional Focus: Africa, South Asia)

·         Albert Bergesen (Sociology, University of Arizona)

·         Sing Chew, (Sociology, Humbolt State University and Helmholtz Centre for Environmental Research, Leipzig, Regional Focus: Southeast Asia

·         Robert Denemark,(Political Science, University of Delaware)

·         Raymond Dezzani (Geography, University of Idaho)

·         Jonathan Friedman (Anthropology, University of California-San Diego, Regional Focus: South-East Asia and Oceania)

·         Barry Gills (Development Studies, University of Helsinki) 

·         Thomas D. Hall (Sociology, Depauw University, Regional Focus: Central Asia)

·         Robert Hanneman (Sociology, University of California-Riverside)

·         Mogens Hansen (Archaeology, Ethnology, Greek & L, University of Copenhagen, Regional Focus: Europe)

·         Ho-Fung Hung (Sociology, Johns Hopkins University, Regional Focus: East Asia),

·         Hiroko Inoue (IROWS, University of California-Riverside, Regional Focus: East Asia),

·         Jed Kaplan (ARVE, Lausanne, Switzerland, Regional Focus: Europe)

·         Andrey Korotayev (Global Studies, Moscow State University, Regional Focus: West Asia, Africa)

·         Bai-Lian Li (Botany and Plant Sciences, University of California-Riverside)

·         Patrick Manning, (University of Pittsburgh, Regional Focus: Africa)

·         Ian Morris (History, Stanford University)

·         Teresa Neal (IROWS, University of California-Riverside, Regional Focus: Indian Ocean),

·         J. B. Owens, (History, Idaho State University, Regional Focus: Europe, South America)

·         Walter Scheidel (History, Stanford University, Regional Focus: Europe)

·         Michael E. Smith, (Anthropology, Arizona State University, Regional Focus: North and Central America)

·         Joseph A. Tainter, (Environment and Society, Utah State University, Regional Focus: North and Central America)

·         William R. Thompson, (Political Science, Indiana University)

·         Peter Turchin (Ecology and Evolutionary Biology Department, University of Connecticut)

·         Douglas White (Anthropology, University of California-Irvine)

Further expertise will be sought from the following scholars: Frances Berdan (Anthropology, California State University-San Bernardino, Regional Focus: North and Central America), Claudio Cioffi-Revilla (Computational Social Science, George Mason University, Regional Focus: Central Asia)  Kajsa Ekholm Friedman (Anthropology, Lund University, Regional Focus: Europe), Peter Grimes (Institute for Research on World-Systems, University of California-Riverside), Victor B. Lieberman, (History, Asian and Comparative History, University of Michigan, Regional Focus: South-East Asia and Oceania), Luis Múzquiz (University of Madrid), Teresa Neal (Sociology, University of California-Riverside: Indian Ocean), Dan Pasciuti (Sociology, Johns Hopkins University), Peter Robertshaw (Anthropology, California State University-San Bernardino, Regional Focus: Africa, South Asia), Peter Taylor (Human Geography, Northumbria University), Marilee Wood (Archaeology, University of the Witwatersrand, Regional Focus: Africa, South Asia), Joseph E. Schwartzberg (Geography, Emeritus, University of Minnesota, Regional Focus: South Asia), Nikolay Kradin (Head and Professor, Department of Social Anthropology,  Far-Eastern National Technical University;  Head and Professor, Department of World History, Archaeology and Anthropology, Far-Eastern Federal University, Regional Focus: Far East, Central Asia), Peter Spufford (History, Professor Emeritus, University of Cambridge, Regional Focus: Europe), Christopher I. Beckwith, (Professor, Central Eurasian Studies at Indiana University, Regional Focus: Central Asia), Norman Yoffee (Near Eastern Studies, Anthropology, Emeritus, University of Michigan, Regional Focus: West Asia ), and Philip L. Kohl (Anthropology, Professor,  Wellesley College, Regional Focus: Central Asia). 

 All these scholars will be invited to participate in an early meeting in which the research plan will be fine-tuned.  The project will also hold an organizational gathering to get feedback on the plans in conjunction with the annual meeting of the International Studies Association (ISA). The SETPOL Data Archive will be housed at the University of California-Riverside. The project will employ formal network analysis, time-series analysis and structural equations modeling to estimate the sizes and directions of the effects of independent variables on scale changes.


Expected Project Significance

This project will contribute to the scientific understanding of the emergence of complexity and hierarchy in human societies. The long-term upsweep of the scale of cities and polities is widely known, but heated debates still rage regarding the proximate and contextual causes of these trends. While certain human and natural factors have been famously hypothesized to be the causes of instances of these scale changes, empirical testing of hypothetical causes has been daunted by the limited comprehensiveness, accuracy, and verifiability of extant data sets on the scale changes. So SETPOL will improve the testability of causal hypotheses by generating a data set that is better in these regards. SETPOL will also contribute to the accurate delineation of the spatial boundaries of trade and political/military interaction networks as they merged and engulfed one another to constitute the contemporary global system of today.[22]  The project will use not only well-established methods for organizing and analyzing data, but also a graph data structure that will allow the combination of GIS with formal network analysis. The project will increase the legibility of the complex spatial processes that led to the emergence of the increasingly global society of today.


Multidisciplinary Character of the Project

The SETPOL database will use standardized geographical network protocols in order to make the data freely available for use by scholars from different disciplines. The framework of comparison is anthropological and world historical. The hypotheses to be tested come from causal models proposed by political scientists, anthropologists and sociologists, especially those who are informed by multidisciplinary perspectives such as geopolitics, human ecology, and the comparative evolutionary world-systems approach. The SETPOL project emphasizes cooperative multidisciplinary exploration of the pathways by which scale changes have occurred in cities and polities. The project will coordinate and collaborate with other multidisciplinary consortia that are currently compiling relevant data. The project will further develop a multidisciplinary theoretical research program by engaging scholars from different disciplines at the levels of empirical measurement and the development and testing of causal models. The SETPOL project will produce articles, monographs and infograms that are intended for a broad multidisciplinary audience.


Broader Impacts

The project's intellectual impact lies in the development of a more holistic multidisciplinary approach to understanding the connections between climate change, demographic expansion and contraction and the size and complexity of human social organization. By confirming or disconfirming the accuracy of contending scientific models of the development of complexity and hierarchy in human societies, the project will help scholars, educators and policy-makers to grasp the main patterns of historical sociocultural evolution.  Such understanding matters for societal responses to major challenges of the 21st century: climate change, ecological degradation, population density, the emergence of global city regions, the rise and fall of hegemonic core powers, and transitions from a unipolar to a multipolar geopolitical structure. The project will also allow provide fresh evidence on the comparisons of similarities and differences across world regions with important implications for explanations of uneven East/West development – issues that have been totemic and fundamental in the development of social sciences since the eighteenth century. The project will have important implications regarding the understanding of past systemic resilience and collapse, and these will have significant implications for the future. The SETPOL project will develop undergraduate and graduate-level courses and research projects to train students to do multidisciplinary research and particularly to develop infographic presentations for teaching scholars and the general public.  


Results from Prior NSF Support. None in last 5 years


The SETPOL project will be managed by the Co-PIs at the University of California-Riverside and the University of California-Los Angeles. Decisions will be made by consensus and in consultation with graduate and undergraduate students who are contributing to the research. Grants Management support will be provided by the University of California-Riverside College of Humanities and Social Sciences and by the Political Science Department at the University of California-Los Angeles.  Co-PIs will discuss management issues by email and at weekly project meetings.

Co-PI Chase-Dunn is Distinguished Professor of Sociology and Director of the Institute for Research on World-Systems at the University of California-Riverside. He has extensively conducted quantitative cross-national comparative research, time series studies of the modern global system and has been developing a research program for quantitatively comparing interpolity networks (world-systems) since he arrived at UC-Riverside from Johns Hopkins University in 2000.

Co-PI Anderson is Emeritus Professor of Anthropology at the University of California-Riverside. He has done ethnographic research in South China and Quintana Roo and he studies political ecology, genocide, animal languages and the diffusion of crops and cuisines across Eurasia.

Professors Chase-Dunn and Anderson will coordinate the activities of students at UC-Riverside who are working on the SETPOL project and they will propose and teach an undergraduate course at UC-Riverside on “The evolution of large-scale, complex settlements and polities

Co-PI Wilkinson is Emeritus Professor of Political Science at the University of California-Los Angeles. He studies international relations, civilizations, warfare, diplomacy and the power configurations of interstate systems since the emergence of states and cities in the early Bronze Age. Professor Wilkinson will supervise student assistants at the University of California Los Angeles and will himself work on the following aspects of the SETPOL project. Wilkinson will hire and train graduate and undergraduate students at UCLA. Professor Wilkinson and the UCLA students will coordinate the effort to specify the spatial boundaries of interaction networks as they have changed over the period under study, i.e. since 1500BCE. This will involve compiling a propositional inventory of the spatial and temporal boundaries of whole human interaction systems by surveying the relevant social science literatures. This effort will then use data on trade, warfare and alliances to specify the best estimates of changes in economic and politico-military network boundaries for all the regions under study. After this is complete each settlement and polity being studied by the SETPOL project will be coded as to its membership in spatially defined trade and warfare-diplomacy  interaction networks. The UCLA group will also organize and extend the coding of changes in the power configurations of interstate networks and participate in the integration of this with the rest of the data structure of the SETPOL project. The UCLA group will participate in the weekly SETPOL project research meetings by means of telecommunication. And they will attend in person the two planned Working Conferences to be held at University of California-Riverside with other project collaborators.  Professor Wilkinson will also develop a course on “The evolution of states systems” that will be offered at UCLA. Professor Wilkinson will also help to author a research proposal to apply for the IBSS Large Interdisciplinary Research Projects in the second year of the project.



1st year (July 1, 2016 - June 30, 2017)

Organize and implement coordination and communication among principal investigators and advisors. Begin weekly SETPOL project meetings at University of California, Riverside. Set up the web site for the research project that presents the proceedings of the research and data gathering.  Hire and train undergraduate and graduate research assistants.  The first Working Conference with the Advisory Committee will be held at UC-Riverside in January 2017. 

Theoretical Issues: Critique the project conceptualization of city and polity scale changes with the participants at the project meetings and the Working Conference. Produce an expanded propositional inventory of explanations of polity and city scale changes from different social science disciplines. Develop a complete propositional inventory of the spatial and temporal boundaries of whole human interaction systems since 1500 BCE.
Develop coding protocols and templates for settlement/city population sizes, empire territorial sizes, core/semiperiphery/periphery status, power configuration of interstate networks, network properties of trade, warfare and alliances, and climate change. Begin search and acquisition of the data through a systematic search of libraries of UCR, UCLA, and Interlibrary Loan Collections as well as digitized databases on the Internet. The first phase of the project will target the ten largest cities and ten largest polities in each world region. Develop initial version of the project database using obtained information.  Fine-tune design of the database.  Locate significant gaps in the data. Make a plan for efficiently filling them given resource constraints. Discuss the degree of consensus among coders for error-control purpose of each coding in the database.  Merge the already-coded data into a prototype of the web-based data entry following the developed common set of coding criteria.

Database and Data Management System:

SETPOL will employ both a standardized spreadsheet and a graph database management system.  Both systems will be managed online and the most updated data will be downloadable so that the collaborating researchers can contribute to data collection and do analyses based on their specific research needs.  The spreadsheet (Excel) format will be used for standard statistical analyses and the graph database will be used for network-based analyses.  For the graph database new kinds of relationships, nodes, and subgraphs can be added as the project proceeds.  

Analyses: Begin testing our baseline hypotheses with the data obtained from preliminary coding.  Discuss, revise, and alter these.  Conduct overlapping coding and examine the degree of consensus of among coders.  Examine the interactions of the groups of cities and polities.

Education: Develop multidisciplinary courses on “The evolution of large-scale, complex settlements and polities” at UCR and UCLA.  Establish an educational web site on “Cites and Empires in World History” which supports the educational goals of multidisciplinary studies.  Graduate and undergraduate student participants in the project will present their own research papers at conferences at American Sociological Association (August), International Studies Association (March), the American Anthropological Association (December) and other local and relevant professional venues. 

2nd year (July 1, 2017 - June 30, 2018)

Coordinate and communicate among principal investigators and advisors in the beginning of the second year to fine-tune the research project and database.  Reflect criticisms and suggestions from advisors to improve the analytical strategies, database development, and hypotheses testing.  Continue weekly Project Meetings at UC-Riverside.  Continue update the research project website.  Students finalize the coding and entering the data on web-based archives by the beginning of 2017. Test hypotheses utilizing completed dataset.  Produce final report of the research.  Create a research proposal to apply for the IBSS Large Interdisciplinary Research Projects in the second year of the project. 
Data: Finalize the coding and entry of data on the project archive.  Conduct final checks of the data by experts on the regions and periods.

Database and Data Management System:

Finalize the development of database.  The database of the finalized format—both CVS-based archive and graph-based datasets—will be made accessible to the public in a user-friendly interface. 

Analyses: Test the hypotheses and alternative hypotheses that have been developed in the project.  Finalize the results of the tests of the research hypotheses. 

Education: Continue courses and student involvement in research. Extend the educational website with links and information on the researches and data archives in cross-disciplinary fields. Students finalize the coding and entering of the data and start analysis of the collected data.  Students present sole-authored and a co-authored research papers at the aforementioned, relevant regional conferences.  Students submit these papers for publication and are involved in publication of books. 

Proposal Writing: submit a December proposal for an IBSS Large Interdisciplinary Research Projects.


Data Management Plan

The SETPOL project will use both a standardized Excel spreadsheet archive and a graph database for its database management system.  The database will be alternately accessed by the coders at the SETPOL data website.  Standardized spreadsheet formats of for cities and polities will be made available for conventional statistical and network analyses. The SETPOL Excel city data base template is at

A graph database will be developed and made accessible to the project researchers for the examination of research questions about network linkages among entities (cities, polities, world regions, PMNs, etc.).

For network analyses, the SETPOL project will use both UCINet (Borgatti, Everett and Freeman 2002) and the graph database application developed as Neo4j. UCINet is the most established network analysis program used by social scientists that allows the calculation of centrality measures for nodes and whole networks, density measures, permutation-based statistical analyses and the identification of clusters and subgroups. The SETPOL project will use UCINet’s advantages in matrix analyses including matrix algebra and multivariable statistics.  Neo4j is an open-source flexible graph database management application. Neo4j allows the storing the data in the form of attributes of entities (including geocodes) and connections among entities.  Each node and edge can have any number of attributes, allowing open, yet complicated queries that can be adjusted to research questions.  The property of index-free adjacency (in which connected nodes physically point to each other in the database) grants significant performance advantages compared with conventional relational databases. The SETPOL project will take advantage of this property for its interconnected relational data which extend across multiple dimensions (variables, their range, their time span) and different units of analysis.  NeoJ4 also has the capability to utilize geocoded entities.


Figure 4:  Graph data structure (Data source: Ciolek, OWTRAD)


Figure 4 is an example of a graph data structure based on entities, attributes and connections among entities.

The SETPOL project will also utilize the graph-based ontology approaches in Geographic Information Systems  such as ArcGIS.  The geospatial information of settlements and polities will be integrated in the GIS domain for constructing cartographic maps. This will be further structured with a time component in a dynamic spatiotemporal visualization format, illustrating changes in ten world regions and the political military and trade networks over time on maps.  The constructed maps will be presented on the SETPOL data archive and made accessible to the collaborating researchers during the project period and to the public after the project period. 


Preservation and Documentation of data

The detailed standards, procedures, and protocols of the data collection will be discussed and determined among PIs and senior advisors at a conference at the beginning of the research project.  The goals of data collection and data preservation will include the following:

·         Archive population sizes, territorial sizes, climate change data, geophysical characteristics of polities, coordinates using the geo URI scheme, polity maps, trade and military network nodes, level of trade, materials transported between the nodes, warfare, alliances and diplomacy, and others.

·         Obtain the consultation of experts for each region to review the data quality and to help resolve instances in which estimates are found to be inconsistent. Expert consultants will also carefully review the final data archive. Remaining disagreements among experts and sources will be included in the final data archive, including indicators of the quality of estimates based on the level of consensus among experts. (for experts’ regions, see pages 9 and 10) Change these pages no. to the right page numbers when we finalize the draft Experts’ region on the above page is not complete

·         Create a catalog of archived information. 

·         Provide technical assistance to research assistants for the collection of data and data input based on the collection standards and protocols in science. 

To ensure that the data will be understood and used appropriately by the general public and scholarly users the data documentation will specify: the data collection method, data collection context, data structure and organization, reports on data reliability and validity, and data quality reports (including descriptions of manipulation of the data that have been conducted).   The project data archive will be included in the data section of the World-Systems Archive (, a publically available archive that has been housed at the University of California-Riverside since 2000 CE. It is a secure institutional repository at UCR that allows access to the academic and public communities.  The PI will preserve the database in accessible and usable form for five years after finalization of the IBSS grant. 

Sharing of data: The data produced by the SETPOL project will be shared among collaborators in the data construction stage and with the general public in the final stage. The SETPOL project collaborates with SESHAT: The Global History Data Bank; the Collaborative for Historical Information and Analysis, Atmosphere Regolith Vegetation (ARVE), Collaborative for Historical Information and Analysis (CHIA) and World History Archives and the Open History Project.

Data entry: The project participants will enter the data in the standardized spreadsheet format.  The spreadsheets are collected by the data manager of the project to be compiled in the main archive file.  The main archive file that is made accessible to the collaborating researchers on data website in the format of CSV and graph-based data format. 

Data improvement: The data will be updated throughout the research period.  The data will be added by incorporating newly published research in the related disciplines as the project proceeds.  The collaborators will use the data to test research hypotheses as the project collects enough data. 

Data adoption: As the database is finalized, the data archive will be made into an open data archive online.  The final data will be made available for public and academic use. 

Policies and provisions for re-use, re-distribution, and the production of derivatives: Rights to copy, adapt, include, distribute, share, reuse, or display the data in other publications are expected.  Public users of this database are free to adapt the data with attribution of author(s). 




Abu-Lughod, Janet. 1989. Before European Hegemony: The World System A.D. 1250-1350. New York: Oxford University Press.

Adams, Robert McCormick. 1981. The Heartland of Cities: Surveys of Ancient Settlement and Land Use on the Central Floodplain of the Euphrates. Chicago: University of Chicago Press

Alexandria Digital Library (ADL) Gazetteer

Algaze, Guillermo. 1993. The Uruk World System: The Dynamics of Expansion of Early Mesopotamian Civilization. Chicago: University of Chicago Press.

Allen, Mitchell. 1995. Contested Peripheries: Philistia in the Neo-Assyrian World-System. Unpublished Ph.D. Dissertation, UCLA.

Anderson, Eugene. N. 2014. Food and Environment in Early and Medieval China. Philadelphia, PA:

            University of Pennsylvania Press.

Anderson, Eugene. N. and C. Chase-Dunn. 2005“The Rise and Fall of Great Powers” in Christopher Chase-Dunn and E.N. Anderson (eds.)  The Historical Evolution of World-Systems. London: Palgrave.

Bairoch, Paul. 1988. Cities and Economic Development Chicago: University of Chicago Press.

Beaujard, Philippe. 2005 The Indian Ocean in Eurasian and African World-Systems Before the Sixteenth Century. Journal of World History 16,4:411-465.

_____.  2009 Les mondes de l’océan Indien Tome I: De la formation de l’État au premier système-monde Afro-Eurasien (4e millénaire av. J.-C. – 6e siècle apr. J.-C.). Paris: Armand Colin. ­­­­­­­­­­­

­_____.  2010. “From Three possible Iron-Age World-Systems to a Single Afro Eurasian World-System.” Journal of World History 21:1(March):1-43.

_____.  2012.  Les mondes de l’océan Indien Tome II:  L’océan Indien, au coeur des globalisations de l’ancien Monde du 7e au 15e siècle. Paris: Armand Colin

Boles, Elson E. 2012. “Assessing the debate between Abu-Lughod and Wallerstein over the thirteenth-century origins of the modern world-syste”Pp. 21-29 in S. J. Babones and C. Chase-Dunn (eds.) Routledge Handbook of World-Systems Analysis. New York: Routledge.

Borgatti, S. P., Everett, M. G. and Freeman, L. C. 2002 UCINET 6 for Windows: Software for Social

            Network Analysis

Brohan, P., R. Allan, E. Freeman, D. Wheeler, C. Wilkinson, and F. Williamson. 2012. "Constraining the temperature history of the past millennium using early instrumental observations" Clim. Past, 8, 1551-1563.

Burton, M.L, C.C. Moore, J.W.M. Whiting, and A.K. Romney. 1996. "Regions based on Social Structure." Current Anthropology 37:87-123.

Carneiro, Robert L. 1978 “Political expansion as an expression of the principle of competitive exclusion,” pp. 205-223 in Ronald Cohen and Elman R. Service (eds.) Origins of the State: The Anthropology of Political Evolution. Philadelphia: Institute for the Study of Human Issues.

_____.  2004. “The political unification of the world: whether, when and how – some speculations.” Cross-Cultural Research 38 (2):162-177.

Chandler, Tertius. 1987. Four Thousand Years of Urban Growth: An Historical Census. Lewiston,N.Y.: Edwin Mellon Press.

Chase-Dunn, C. and Thomas D. Hall. 1997. Rise and Demise: Comparing World-Systems Boulder,

            CO.: Westview.

Chase-Dunn, C.  and Kelly M. Mann.1988. The Wintu and Their Neighbors: A Small World-System in Northern California, University of Arizona Press.

Chase-Dunn, C. and Andrew K. Jorgenson. 2003. “Regions and Interaction Networks: an institutional materialist perspective.International Journal of Comparative Sociology 44(1):433-450.

Chase-Dunn, C., Susan Manning, and Thomas D. Hall, 2000 "Rise and Fall: East-West Synchronicity and Indic Exceptionalism Reexamined" Social Science History 24,4: 721-48(Winter).

Chase-Dunn, C. and Susan Manning, 2002 "City systems and world-systems: four millennia of city growth and decline," Cross-Cultural Research 36, 4: 379-398 (November).

Chase-Dunn, C. and Hiroko Inoue. 2011. “Explanations of scale changes in settlement and polity sizes” IROWS Working Paper # 67

Chase-Dunn, C  and Bruce Lerro. 2014. Social Change: Globalization from the Stone Age to the

            Present. Boulder, CO: Paradigm

Chase-Dunn, C. David Wilkinson, E.N. Anderson, Hiroko Inoue and Robert Denemark  2015a “Time-

            mapping globalization since the Bronze Age” IROWS Working Paper

            #  100

Chase-Dunn, C. Hiroko Inoue, Alexis Alvarez, Rebecca Alvarez,  E. N. Anderson and Teresa Neal 2015b “Uneven Political Development: Largest Empires in Ten world Regions and the Central International System since the Late Bronze Age” presented at the annual conference of the California Sociological Association,  Sacramento,  November 13 IROWS Working Paper #85

Chew, Sing C. 2001. World ecological degradation: accumulation, urbanization, and deforestation, 3000 B.C.-A.D.  Walnut Creek, CA: Altamira Press

_____.  2007. The Recurring Dark Ages: ecological stress, climate changes, and system transformation Walnut Creek, CA: Altamira Press

_____. 2014 “The Southeast Asian connection in the first Eurasian world economy,

            200 BC- AD 500” Journal of Globalization Studies, Vol. 5 No. 1: 82–109

CHGIS: the China Historical Geographic Information System

CHIA: Collaborative for Historical Information and Analysis

Christian, David. 2004. Maps of Time. Berkeley: University of California Press.

Ciolek, Matthew n.d. OWTRAD: Old World Trade Routes Project.

Collaborative for Historical Information and Analysis, University of Pittsburg

Collins, Randall. 1981 “Long term social change and the territorial power of states,” Pp. 71-106 in R. Collins (ed.) Sociology since Midcentury. New York: Academic Press.

Collins, Randall. 1992. “The Geographical and Economic World-Systems of Kinship-Based and Agrarian-Coercive Societies.” Review 15(3):373-88. 

Collins, Randall. 1999. Macro-History: Essays in Sociology of the Long Run. Stanford: Stanford University Press.

Daftlogic n.d.

Diamond, Jared. 2005. Collapse. New York:  Viking

Eckhardt, William. 1992. Civilizations, Empires and Wars: A Quantitative History of War. Jefferson, NC: McFarland.

Ekholm, Kasja and Jonathan Friedman. 1982. “Capital Imperialism and Exploitation in the Ancient World-Systems.” Review 6(1):87-110.

Fagan, Brian. 2005. The Great Warming: Climate Change and the Rise and Fall of Civilizations. New York:Bloomsbury

Fletcher, Roland. 1995. The Limits of Settlement Growth. Cambridge:  Cambridge University Press.

_____.  n.d. City and Polity Data Files, Personal communication

Frank, Andre Gunder and Barry Gills. 1994. The World System: 500 or 5000 Years? London: Routledge.

Frank, Andre Gunder 1998 Reorient: Global Economy in the Asian Age. Berkeley: University of

            California Press.

_____.  2014 Reorienting the 19th Century: Global Economy in the Continuing Asian Age. Boulder, CO: Paradigm Publishers.

Goldstone, Jack A. 1991 Revolution and Rebellion in the Early Modern World. Berkeley: University of

            California Press

_______________ 2009 Why Europe?: the Rise of the West in World History, 1500-1850. New York:


Hawley, Amos. 1950. Human Ecology: A Theory of Community Structure. New York: Ronald Press Co.

Honeychurch, William. 2013. “The Nomad as State Builder: Historical Theory and Material Evidence from Mongolia” Journal of World Prehistory 26:283–321.

Innis, Harold. 1972 [1950]. Empire and Communications. Toronto: University of Toronto Press.

Inoue, Hiroko, Alexis Álvarez, Kirk Lawrence, Anthony Roberts, Eugene N Anderson and Christopher Chase-Dunn. 2012. “Polity scale shifts in world-systems since the Bronze Age: A comparative inventory of upsweeps and collapses” International Journal of Comparative Sociology

Inoue, Hiroko, Alexis Álvarez, Eugene N. Anderson, Andrew Owen, Rebecca Álvarez, Kirk Lawrence and Christopher Chase-Dunn. 2015.Urban scale shifts since the Bronze Age: upsweeps, collapses and semiperipheral development” Social Science History Volume 39 number 2, Summer

Johnson, Allen W. and Timothy Earle. 1987. The Evolution of Human Societies: From Foraging Group to Agrarian State. Stanford: Stanford University Press.

Kaplan, Jed. n.d. PopMap: Population Evolutions with Google Map.

Kardulias, P. Nick, ed. 2015. The Ecology of Pastoralism. Boulder: University Press of Colorado.

Khaldūn, Ibn. 1958. The Muqaddimah. Vol. 1. Tr. and ed. by Franz Rosenthal. New York:  Pantheon Books.

Kirch, Patrick. 1984. The Evolution of Polynesian Chiefdoms. Cambridge: Cambridge University Press

_____.  1991. “Chiefship and competitive involution: the Marquesas Islands of Eastern Polynesia” Pp. 119-145 in Timothy Earle (ed.) Chiefdoms: Power, Economy and Ideology. Cambridge: Cambridge University Press.

Korotayev, Andrey. 2005. “A compact macro-model of world-system evolution” Journal of

            World-Systems Research.11 (1): 79-93.

Kroeber, Alfred L. 1944 Configurations of Culture Growth Berkeley: University of California Press

La Lone, Darrell. 2000. "Rise, Fall, and Semiperipheral Development in the Andean World-System." Journal of World-Systems Research 6 (1):68-99.

Larsen, Mogens Trolle. 1976. The Old Assyrian City-State and its Colonies. Copenhagen: Akademisk Forlag.

Lattimore, Owen. 1940 Inner Asian Frontiers of China. New York: American Geographical Society. Boston: Beacon Press.

Lenski, Gerhard. 2005. Ecological-Evolutionary Theory. Boulder, CO: Paradigm Publishers

            Mann, Michael. 1986. The Sources of Social Power Volume I: A History of Power From the Beginning to A.D. 1760. New York, NY: Cambridge University Press.

Lewis, Martin W, and Karen E. Wigen 1997 The Myth of the Continents: A critique of metageography. Berkeley: University of California Press.

Manning, Patrick. 2013 Big Data in History, New York: St Andrew’s Press (Palgrave MacMillan)

Lieberman, Victor.  2003.  Strange Parallels:  Southeast Asia in Global Context, c. 800-1830.  Vol. 1: Integration on the Mainland.  Cambridge:  Cambridge University Press.

_____.  2009.  Strange Parallels:  Southeast Asia in Global Context, c. 800-1830.  Vol 2: Mainland Mirrors: Europe, Japan, China, South Asia, and the Islands.  Cambridge:

            Cambridge University Press.

Liverani, Mario. 2014. The Ancient near East: History, Society and Economy. London: Routledge.

McAnany, Patricia A. and Norman Yoffee, Eds. 2010. Questioning Collapse:  Human Resilience, Ecological Vulnerability and the Aftermath of Empire.  Cambridge:  Cambridge University Press.

McIntosh, Roderick J., Joseph A. Tainter and Susan Keech McIntosh (eds.) 2000. The Way the Wind Blows: Climate, History and Human Action. New York: Columbia University Press.

McNeill, J. R. and William H. McNeill. 2003. The Human Web: A Bird's Eye View of World History. New York: W. W. Norton. 

Melko, Matthew and Leighton R. Scott (eds.) 1987. The Boundaries of Civilizations in Space and Time.  Lanham, MD:  University Press of America.

Meyer, John W. 2009. World Society. Edited by Georg Krukcken and Gili S. Drori. New York:

            Oxford University Press.

Modelski, George. 2003. World Cities:  –3000 to 2000. Washington, DC:  Faros 2000

Modelski, George and W. R. Thompson. 1996. Leading sectors and world powers: the coevolution of global politics and economics. University of South Carolina Press.

_____.  Tessaleno Devezas and William R. Thompson (eds.) 2008

            Globalization As Evolutionary Process: Modeling Global Change. London: Routledge.

Mogens Herman Hansen (ed.). 2000. A comparative study of thirty city-state cultures: an investigation.  conducted by the Copenhagen Polis Centre, Det Kongelige Danske Videnskabernes Selskab, (Historisk-filosofiske skrifter, 21).

Mogens Herman Hansen (ed.). 2002. A comparative study of six city-state cultures: an investigation. Det Kongelige Danske Videnskabernes Selskab (Historisk-filosofiske skrifter, 27). 

Mogens Herman Hansen and Thomas Heine Nielsen (eds.). 2004. An Inventory of Archaic and Classical Poleis: An Investigation. Conducted by The Copenhagen Polis Centre for the Danish National Research Foundation. Oxford: Oxford University Press.

Morris, Ian. 2010. Why the West Rules—For Now.  New York:  Farrer, Straus and Giroux

_____.  2013. The Measure of Civilization. Princeton, NJ: Princeton University Press.

Morris, Ian  and Walter Scheidel (eds.) The Dynamics of Ancient Empires: State Power from

            Assyria to Byzantium. New York: Oxford University Press.

Nichols, Deborah L, Thomas. H. Charlton (eds.) 1997. The Archaeology of City-states: cross-cultural approaches.  Washington: Smithsonian Institution Press.

Open History Project n.d. Russian Foundation for Basic Research

Ortman, Scott G., Andrew H. F. Cabaniss, Jennie O. Sturm, and Luı´s M. A. Bettencourt. 2014. "The Pre-History of Urban Scaling" PLOS ONE. 9 (2)

Ortman, Scott G. Andrew H. F. Cabaniss, Jennie O. Sturm and Luís M. A. Bettencourt. 2015. "Settlement scaling and increasing returns in an ancient society" Science Advances, 1 (2)

Owens, J.B., Anderson Sandes, Barbara Stephenson, David Dixon and Catherine Zajanc n.d. A. Geographic Information Systems (GIS) Training Manual for Historians and Historical Social Scientists.

Pasciuti, Daniel. 2002. “A measurement error model for Estimating the Population Sizes of Preindustrial Cities

Pasciuti, Daniel and Christopher Chase-Dunn. 2002. “Estimating the Population Sizes of


Pomeranz, Kenneth 2000 The Great Divergence: Europe, China and the Making of the Modern World

Economy. Princeton: Princeton University Press.

Quigley, Carroll. 1961. The Evolution of Civilizations. Indianapolis: Liberty Press.

Rozman, Gilbert. 1973. Urban Networks in Ching China and Tokogawa Japan. Princeton, NJ:

            Princeton University Press.

SESHAT : The Global History Data Bank

Scheidel, Walter. 2009. “From the “great convergence” to the “first great divergence”:

            Roman and Qin-Han state formation” Pp. 11-23 in Walter Scheidel (ed.)  Rome and

            China: Comparative Perspectives on Ancient World Empires. New York: Oxford University Press.

_____.  ORBIS: The Stanford Geospatial Network Model of the Roman World


_____.  and Sitta Von Reden (eds.) The Ancient Economy. New York: Routledge.

Sherratt, Andrew G.  1993a. "What Would a Bronze-Age World System Look Like?  Relations Between Temperate Europe and the Mediterranean in Later Prehistory."  Journal of European Archaeology 1:2:1-57.

_____.  1993b. "Core, Periphery and Margin:  Perspectives on the Bronze Age."  Pp. 335-345 in Development and Decline in the Mediterranean Bronze Age, edited by C. Mathers and S. Stoddart.  Sheffield:  Sheffield Academic Press.

_____.  1993c. "Who are You Calling Peripheral?  Dependence and Independence in European Prehistory."  Pp.  245-255 in Trade and Exchange in Prehistoric Europe, edited by C. Scarre and F. Healy.  Oxford:  Oxbow (Prehistoric Society Monograph).

_____.  1993d. "The Growth of the Mediterranean Economy in the Early First Millennium BC."  World Archaeology 24:3:361-78.

Schwartzberg, Joseph E. (ed) 1992. A Historical Alas of South Asia. Second Impression, with Additional Material. New York: Oxford University Press.

New York: Oxford University Press. Digital South Asia Library, Center for Research Libraries

Skinner, G. William (ed.) 1977. The City in Late Imperial China Stanford: Stanford University Press.

Smith, Charlotte Ann. 2002. “Concordant change and core-periphery dynamics: a synthesis of highland Mesoamerican archaeological data” University of Georgia, PhD dissertation.

Smith, Michael E. 2005. “City size in late postclassic Mesoamerica” Journal of Urban History 31,

            4: 403-434.

Smith, Michael E. and Lisa Montiel 2001 “The Archaeological Study of Empires and Imperialism in Pre-Hispanic Central Mexico” Journal of Anthropological Archaeology 20, 245–284

Smith, Michael E. Gary M. Feinman, Robert  D. Drennan, Timothy Earle and Ian Morris. 2012.

            “Archaeology as a social science” PNAS, 109. 20: 7617–7621 (May 15)

Sturtevant, William C. General Editor. 1978-2007. Handbook of North American Indians. Washington, D.C.: Smithonian Institution.

Sutton, Mark Q. and E.N. Anderson 2014  Introduction to Cultural Ecology. Lanham, MD: Altamira


Taagepera, Rein. 1978a. "Size and duration of empires: systematics of size" Social Science Research. 7:108-27.

_____.  1978b. "Size and duration of empires: growth-decline curves, 3000 to 600 B.C." Social Science Research, 7:180-96.

_____.  1979. "Size and duration of empires: growth-decline curves, 600 B.C. to 600 A.D." Social Science History 3 (3-4):115-38.

_____.  1997. “Expansion and contraction patterns of large polities: context for Russia.” International Studies Quarterly. 41(3):475-504.

Tainter, Joseph. 1988. The Collapse of Complex Societies. Cambridge:  Cambridge University Press.

Teggart, Frederick J. 1939. Rome and China: A Study of Correlations in Historical Events. Berkeley, CA: University of California Press.

Thompson, William R and Kentaro Sakuwa 2013 “Was Wealth Really Determined in 8000 BCE, 1000 BCE, 0 CE, or Even 1500 CE? Another, Simpler Look” Cliodynamics 4,1: 2-29

Tilly, Charles. 1984. Big Structures, Large Processes, Huge Comparisons. New York, NY: Russell Sage.

Turchin, Peter. 2003. Historical Dynamics. Princeton, NJ: Princeton University Press.

_____.  2011. “Warfare and the Evolution of Social Complexity: a Multilevel Selection Approach” Structure and Dynamics Vol. 4, Iss. 3, Article 2:1 -37

Turchin, Peter. and T. D. Hall. 2003. Spatial synchrony among and within world-systems: insights from theoretical ecology. Journal of World Systems Research 9,1

Turchin, Peter and Sergey Nefadov. 2009. Secular Cycles. Princeton, NJ: Princeton University Press.

Turchin, Peter, Thomas E.Currie, Edward A.L. Turner and Sergey Gavrilets 2013 “War, space, and the evolution of Old World complex societies” PNAS October vol. 110 no. 41: 16384–16389 Appendix:

United Nations 2011 World Urbanization Prospects: The 2011 Revision: Methodology

University of Sydney Timemap Project

Wallerstein, Immanuel. 1984. “The three instances of hegemony in the history of the capitalist world-economy.” Pp. 100-108 in Gerhard Lenski (ed.) Current Issues and Research in Macrosociology, International Studies in Sociology and Social Anthropology, Vol. 37. Leiden: E.J. Brill.

_____.  1995. “Hold the tiller firm: on method and the unit of analysis” Pp. 239-247 in Stephen K. Sanderson (ed.) Civilizations and World-Systems. Walnut Creek, CA: Altamira Press.

_____.  2011. [1974]. The Modern World-System I: Capitalist Agriculture and the Origins of the European World-Economy in the Sixteenth Century. Berkeley: University of California Press.

White, D. R., Natasa Kejzar and Laurent Tambayong. 2006. “Oscillatory dynamics of city-size distributions in world historical systems”. Pp. 190-225 in G. Modelski, T. Devezas and W. Thompson, (eds.) Globalization as Evolutionary Process: Modeling, Simulating, and Forecasting Global Change. London: Routledge.

Wilkinson, David. 1987. “Central Civilization.” Comparative Civilizations Review 17:31-59.

_____.  1991. “Core, peripheries and civilizations,”Pp. 113-166 in C. Chase-Dunn and T.D. Hall (eds.) Core/Periphery Relations in Precapitalist Worlds. Boulder, CO: Westview Press

Wilkinson, David.  2003. “Civilizations as Networks: Trade, War, Diplomacy, and Command-Control.” Complexity Vol.8 No. 1, 82-86 

_____. 2014. "The Rise and Demise of (Genuine) Capitalist Imperialism: 13th-16th century Venice, Genoa and the Hanse" International Studies Association Conference in 2014

_____.  1992a. "Decline phases in civilizations, regions and oikumenes." A paper presented at the annual meetings of the International Studies Association, Atlanta, GA. April 1-4.

_____.  1992b. "Cities, civilizations and oikumenes:I." Comparative Civilizations Review 27:51-87 (Fall).

_____.  1993. “Cities, civilizations and oikumenes:II” Comparative Civilizations Review 28: 41-72.

_____.  2004. The Power Configuration Sequence of the Central World System, 1500-700 BC Journal of World-Systems Research Vol. 10, 3.

Wilkinson, Toby C., Susan Sherratt and John Bennet. 2011. Interweaving Worlds: Systemic Interactions in Eurasia, 7th to 1st Millennia BC. Oxford: Oxbow Books.

Wissler, Clark. 1927. “The Culture Area Concept in Social Anthropology.” American Journal of Sociology 32(6):881-891.

Wohlforth, William C., Richard Little, Stuart J. Kaufman, David Kang, Charles A Jones, Victoria Tin-Bor Hui, Arther Eckstein, Daniel Deudney and William L Brenner. 2007. “Testing balance of power theory in world history” European Journal of International Relations 13,2: 155-185.

Wong, R. Bin 1997 China Transformed: Historical Change and the Limits of European Experience.

            Ithaca: Cornell University Press.

World History Archives:

Wright, Henry T. 2006. “Atlas of Chiefdoms and Early States” Structure and Dynamics 1,4. Available at:   



[1] The term “settlement” includes camps, hamlets, villages, towns and cities. Settlements are spatially bounded for comparative purposes as the contiguous built-up area.

[2] In a subsequent phase of this project we intend to expand the framework to include prehistoric camps, villages and towns in small-scale stateless polities as well as early Bronze Age cities and states. For reasons of feasibility the first phase will focus on cities and empires over the past 3500 years. We will however also study the nomads and hill peoples who were in interaction with states and cities in this period.

[3] “Polity” is a general term that means any organization with a single authority that claims control over a territory or a group of people. This includes bands, tribes, chiefdoms, states and empires. In this proposal the term polity is shorthand for states, city-states, territorial empires, colonial empires and modern nation-states.

[4] We distinguish between an “upswing,” which is any upturn in a growth/decline sequence, and an “upsweep”, which goes to a level that is more than 1/3 higher than the average of three prior peaks (Inoue et al 2012).

[5]  Walter Scheidel (2009) contends that there were two great divergences between China and the West. The one that occurred in the 18th and 19th centuries has received a lot of attention from  Kenneth Pomeranz (2000), who named it “the great divergence”.  Scheidel (2009) notes that there was an earlier great divergence between China and the West.  Both the Roman and the Han empires managed to bring huge territories under a single authority, but after they declined different things happened in the West and the East.  In the East the decline of the Han was followed, after a rather short interval, by the rise of the Tang dynasty, which was nearly as large as the Han dynasty had been. In the West, after the fall of Rome another empire of a similar huge size, uniting the entire Mediterranean littoral, never rose again.  This was Scheidel’s first great divergence.

[6] A larger overview of theoretical approaches to explaining the causes of urban and polity cycles and scale changes (Chase-Dunn and Inoue 2011) includes very general functionalist learning theories of sociocultural evolution from biologists and ecologists, including complexity theories, multilevel selection and panarchy.  The SETPOL theoretical and propositional inventory will include these.

[7] This project will use Common Era (CE) and Before Common Era (BCE) to indicate calendar years.

[8] Use of the word “evolution” still requires explanation. We mean long-term patterned change in social structures, especially the development of complex divisions of labor and hierarchy. We do not mean biological evolution, which is a very different topic, and neither do we mean “progress,” a normative notion that is unnecessary for the scientific study of social change.


[9] Studying changes in the population sizes of largest cities is a useful window on polities, but it does not capture overall changes in the population sizes of polities (studied most recently by Turchin and Nefadov (2009) and neither does it reflect important changes in the distribution of city sizes studied by many urban geographers (e.g. Rozman 1973).

[10] Gilbert Rozman’s (1973) illuminating comparison of the development of Japanese and Chinese urban systems shows that the emergence of an integrated city system with middle-sized cities performing regional functions occurred much faster but later, in Japan than it did in China, because the Japanese were able to benefit from knowing about the Chinese experience.

[11] The idea of the Central Political/Military Network (PMN) is derived from David Wilkinson’s (1987) definition of “Central Civilization.” It spatially bounds a system in terms of a set of allying and fighting polities.  The Central PMN is the interstate system that was created when the Mesopotamian and Egyptian interstate networks became directly connected with one another in about 1500 BCE.  The Central PMN expanded in waves until it came to encompass the whole Earth in the 19th century CE.  Because it was an expanding system, its spatial boundaries changed over time. This project will examine Wilkinson’s decisions about when and where the Central PMN expanded.     

[12] For example polities specializing in pastoralism emerged from the interaction of nomadic hunter-gatherers with farmers (Lattimore 1940)

[13] We are indebted to those prodigious coders who made quantitative comparative studies of settlements and polities possible: Tertius Chandler, Rein Taagepera and George Modelski.

[14] Of course territorial size is only a rough indicator of the power of a polity because areas are not equally significant with regard to their ability to supply resources. A desert empire may be large but weak. But this rough indicator is quantitatively measureable in different world regions over long periods of time, so it is valuable for comparative historical research.

[15] Estimating the area within a polity has gotten much easier. We use “daftlogic” to calculate the areas within a polygon (Daftlogic n.d.).

[16] Coding the total populations of polities will make it possible to examine the relationship between urban population growth/decline and the population growth/decline of the larger polity of which the cities are a part. Our project will collaborate with Seshat on this and other variables.

[17] The Geo URI scheme is a Web-based map annotation system using URI (a Uniform Resource Identifier) that allows the representation independently of any Web resources (or specific URL).  The Geo URI scheme identifies geographic location in a two- or three-dimensional coordinate reference system. 


[18] The study by Ortman et al (2014) contends that population density usually increases with the areal sizes of settlements.

[19] This corresponds to what the United Nations methodology calls “urban area” (UN 2011).

[20] Roland Fletcher (n.d. personal communication) has also gathered estimates of the sizes of important cities by reading widely about individual cities and coding all the estimates he could find. Fletcher’s data are different from the others in that he includes all the estimates he could find without editing and without collapsing estimates temporally. The others try to guess the sizes of cities at long intervals, whereas Fletcher presents the exact years to which the estimates that he has found apply. We will incorporate Fletcher’s estimates into the project city data set. The SETPOL project will also collaborate with ARVE in Lausanne, Switzerland and with the Open History Project. 

[21] Michael E. Smith (2005) provides city size estimates for Late Postclassic Mesoamerica (1200-1520 CE) but it is not possible to count cycles and sweeps because changes in city sizes over this time period are not known. Charlotte Ann Smith (2002) has estimates over time for largest Mesoamerican cities, but the temporal resolution is not fine enough to see cycles and sweeps. The Ortman et al 2014 study of settlement sizes in the valley of Mexico also has temporal resolution based on archaeological phases that are too widely spaced for the study of cycles and sweeps.

[22] This issue will be investigated in a workshop on the spatial bounding of world-systems (see Chase-Dunn, Wilkinson, Anderson, Inoue and Denemark 2015).