Correlates Of War Research Articles

Mad CoW: A Reply to Gibler and Miller

Abstract In Divided Armies, I argue that inequality within armies (“military inequality”) has shaped their battlefield performance in conventional wars since 1800. Gibler and Miller (2022) are unpersuaded. They raise a flurry of concerns about the cross-national evidence and one statistical analysis in the book’s Chapter 4. In particular, they maintain that Project Mars, the book’s dataset, offers nothing new compared to the Correlates of War (CoW). I find their criticisms misplaced. I use their own statistical models for reanalyzing Project Mars to demonstrate that military inequality is an important driver of battlefield performance across six different measures in all types of CoW wars over the past 200 years. We should build, not bury, a research program that further explores the relationship between inequality and political violence.

Thailand’s Balancing Behavior, 1947–1991: Some Empirical Evidence

This study examines the determinants that shaped the balancing behavior of Thailand from 1947 to 1991 by testing hypotheses developed from arguments on three competing theories of balancing behavior, namely the systemic balance of power and balance of threat theories, as well as Martin’s simple model of balancing behavior. We found that a combination of power, geographic distance, and perceived offensive intentions was the factor that prompted Thailand to balance against threatening states. The finding was found using quantitative data extracted from the Correlates of War (COW) Project and the Alliance Treaty Obligations and Provisions (ATOP) Project and those generated by Expected Utility Generation and Data Management Program (EUGene) software to test the hypotheses. The statistical evidence confirms the historical narrative of Thai diplomatic history: that is, Thailand did not try to balance against communist China, its giant neighbor, but rather against Vietnam and Cambodia, which were perceived as essentially dangerous to the country’s security and territorial integrity. In addition, we found that the major-power capability concentration of the Cold War international system had a mild effect on Thai behavior. However, it is difficult to generalize how such systemic attributes dictated directions in Thai foreign policy.

States and their international relations since 1816: introducing version 2 of the International System(s) Dataset (ISD)

ABSTRACTWe introduce version 2 of the International System(s) Dataset (ISD), a register of sovereign states across the 1816–2016 period that include numerous states that are missed in commonly used datasets like the Correlates of War (COW) Project. Whereas ISD version 1 identified 363 states between 1816 and 2011, version 2 identifies 482. This version also records valuable information on a range of corollary variables, including start dates, end dates, estimated population sizes, diplomatic relations with Europe, conflict episodes, the existence of borders, and the location of capital cities. This dataset makes an important contribution to the study of international relations. It provides a more accurate understanding of the development of the international system over the last two centuries, it moves beyond the Eurocentric bias that sits at the heart of existing quantitative IR scholarship, and it will enable scholars to pursue a range of research topics such as the historical importance of state borders and boundaries, the practices surrounding recognition, and the frequency and intensity of conflict across regions. In this article, we discuss the existing state system membership lists and show how the ISD addresses their shortcomings. We outline the key concept and operationalization of statehood that the ISD adopts. We detail the variables included in this version of the ISD, discuss the data collection process, and show temporal and spatial distributions that illustrate the uniqueness of the ISD. Finally, we demonstrate the utility of bringing the ISD into one of many potential research topics: the study of conflict.

A deeper look at interstate war data: Interstate War Data version 1.1

This paper accomplishes two related goals. Firstly, it presents version 1.1 of the Interstate War Data (IWD) data set. IWD is a data set of all interstate wars, using Correlates of War (COW) rules but improving on COW by repairing the high number of coding errors in COW and more accurately and precisely treating multilateral wars. IWD 1.1 makes important improvements over IWD 1.0, such as describing interstate wars and war participants previously neglected by COW and IWD 1.0 and extending the temporal range forward to 2013. It also is the first data set to provide a systematic list of all interstate wars back to 1816 with at least 500 battle deaths (COW and IWD 1.0 only listed those conflicts with at least 1000 battle deaths). Secondly, the paper discusses important issues in collecting data on interstate wars, especially collecting reliable data on battle dead. Battle dead data are critical both for constructing data sets and for testing hypotheses, but frequently battle dead estimates vary widely, and come from sources of varying quality. The paper discusses the importance of using reliable sources, and in particular of minimizing reliance on military encyclopedias.

A Revised Look at Interstate Wars, 1816–2007

Interstate war data are critical for many important research areas in international relations. Scholars working in these areas frequently rely on the Correlates of War (COW) interstate war data. This article analyzes the COW interstate war data version 4.0, covering the years 1816 through 2007. Using COW coding criteria, the article finds that in more than 30 percent of the ninety-five COW interstate wars, codings of at least one of the key variables—existence of the war, list of participants, initiator, and outcome—needs to be revised. This article describes a revised data set on interstate wars that incorporates these revisions. The data set includes a metric for breaking apart large, multilateral wars such as the World Wars into component wars. For each participant in multilateral wars, it provides information on exactly which states that participant fought, and specific initiation and outcome codings for that participant.

Theme and Variations

Since its establishment in 1963, the Correlates of War (COW) project has sought to build cumulative knowledge about international conflict through the application of the scientific method to the study of militarized interstate behavior. Early analyses from the COW project found substantial variation in the causal model of war across the nineteenth and twentieth centuries, but COW scholars later sought to develop a general model of war that avoided post hoc historical periodization. We use out of sample cross validation to evaluate the plausibility of assuming temporal homogeneity for statistical models of international conflict that span the nineteenth and twentieth centuries. Our results suggest that the causal model of war changes substantially across historical eras. In particular, great care should be taken in generalizing Cold War findings to other historical eras. Our findings demonstrate the importance of exploring temporal variation in the causal model of war.

Surrounded by wars: Quantifying the role of spatial conflict spillovers

We apply panel estimation methods to test how the incidence of war in neighbourhood countries affects the incidence of war in the domestic country. This study finds positive and significant evidence of “spatial conflict spillover”: higher incidence in the neighbourhood increases domestic country involvement in war. We also provide some new evidence on other correlates of war. Particularly interesting are the results concerning the effect of democracy. An increase in the level of democracy increases the incidence of interstate war and reduces the incidence of civil war. However, this latter effect kicks in only past a certain initial level of democracy.

Greed or Grievance, a Contextual Reconciliation?

We use a simple coordination game to suggest that rebels are more likely to use grievance to coordinate rebellion against strong states. The actual feasibility of conflict then matters more in weaker states. We use Collier, Hoeffler, & Rohner’s (2009) data in the context of state power to indirectly test this hypothesis. We find, consistent with our theory, that their “significant” greed or feasibility variables matter more for explaining conflict in weaker states. We therefore suggest that a search for the universal correlates of war may be problematic. Moreover, even if these correlates exist, parametric point estimates of the marginal effect of such correlates of war may be misleading since the size of such an effect may differ contextually. Thus, using such point estimates devoid of context to capture the potential effect of policy levers may lead to erroneous policy.

Event order generation using Reference Event based qualitative Temporal (REseT) relations in Time Event Ontology

AbstractOWL (Web Ontology Language) is the standard language for Semantic Web and is used in defining ontologies for Web. Temporal event data are ubiquitous in nature. Temporal data can be represented qualitatively using temporal relations in OWL, enabling temporal ordering of events which plays a vital role in task planners. The basic Allen’s temporal interval relations can be used to describe relations in OWL. Allen’s interval algebra is a well known formalism used to represent and reason the temporal knowledge. In this work, Allen’s interval algebra is extended by Reference Event based Temporal (REseT) relations to reduce the ambiguity in the before relation. The extended formalism is used in the representation of relations between time intervals and the viability of ordering of events in ontology is elucidated. This paper proposes a temporal knowledge representation and reasoning based event ordering system which helps in the temporal ordering of events. The advantage of this method is that it does not introduce any additional constructs in OWL and hence the existing reasoning tools and DL based query languages are capable of generating the linear order of events. The system is investigated experimentally using the COW (Correlates of War) dataset and has been evaluated using the Percent_ Similarity measure.

Does conflict disrupt growth? Evidence of the relationship between political instability and national economic performance

Current empirical growth models limit the determinants of country growth to geographic, economic, and institutional variables. This study draws on conflict variables from the Correlates of War (COW) project to ask a critical question: how do different types of conflict affect country growth rates? It finds that wars slow the economy. Estimates indicate that civil war reduces annual growth by 0.01–0.13 percentage points, and high-intensity inter-state conflict reduces annual growth by 0.18–2.77 percentage points. On the other hand, low-intensity conflict slows growth much less than high-intensity conflict, and may slightly increase it. The detrimental effect of conflict on growth is intensified when examining non-democracies, low-income countries, and countries in Africa.

Guest Editors' foreword: democracies at war

Click to increase image sizeClick to decrease image size Notes 1. Research for this special edition was supported by an Australian Research Council Discovery Grant. We are grateful to Dan Halvorson and Lee Morgenbesser for able research assistance. 2. See Chan (1984 Chan, Steve. 1984. Mirror, mirror on the wall … are the freer countries more pacific?. Journal of Conflict Resolution, 28(4): 617–48. [Crossref], [Web of Science ®] , [Google Scholar]), Doyle (1983 Doyle, Michael W. 1983. Kant, liberal legacies, and foreign affairs. Philosophy and Public Affairs, 12(3): 205–35. [Web of Science ®] , [Google Scholar]), Maoz and Abdolali (1989 Maoz, Zeev and Abdolali, Nasrin. 1989. Regime types and international conflict, 1816–1976. Journal of Conflict Resolution, 33(1): 3–35. [Crossref], [Web of Science ®] , [Google Scholar]), Moaz and Russett (1993), Rousseau et al. (1996), Rummel (1979 Rummel, R.J. 1979. Understanding conflict and war. Volume 4: war, power, peace, Beverly Hills, CA: Sage. [Google Scholar]) and Weede (1984 Weede, Erich. 1984. Democracy and war involvement. Journal of Conflict Resolution, 28(4): 649–64. [Crossref], [Web of Science ®] , [Google Scholar]). On the monadic theory regarding states in transition to democracy, see Rousseau et al. (1996) and Snyder and Mansfield (1995). 3. On the limitations of definitions, see, for example, Kegley and Hermann (1999: 101), who argue that the definition of military intervention is not clear, and Spiro (1994), who makes a similar claim regarding the vagueness of the definition of democracy, liberalism and war. On the merits of various indices, such as the Polity data set and Correlates of War (COW), see Munck and Verkuilen (2002 Munck, Gerardo and Verkuilen, Jay. 2002. Conceptualizing and measuring democracy: evaluating alternative indices. Comparative Political Studies, 35(1): 5–54. [Crossref], [Web of Science ®] , [Google Scholar]). 4. As Elman (1997 Elman , Miriam 1997 . Paths to peace: is democracy the answer? Cambridge , MA : The MIT Press . [Google Scholar]) argues, part of the problem has been in case selection, with an overemphasis on cases involving the United States and excessive focus on the Fashoda Crisis and the Spanish–American War. 5. On methodological-based critiques, see Gartzke (1998 Gartzke, Erik. 1998. Kant we all just get along? Opportunity, willingness, and the origins of the democratic peace. American Journal of Political Science, 42(1): 1–27. [Crossref], [Web of Science ®] , [Google Scholar], 2000 Gartzke, Erik. 2000. Preferences and the democratic peace. International Studies Quarterly, 44(2): 191–212. [Crossref], [Web of Science ®] , [Google Scholar]); on substantive critiques, see Copeland (1996 Copeland, Dale C. 1996. Economic interdependence and war: a theory of trade expectations. International Security, 20(4): 5–41. [Crossref], [Web of Science ®] , [Google Scholar]), Farber and Gowa (1997 Farber, Henry S. and Gowa, Joanne. 1997. Common interests or common polities? Reinterpreting the democratic peace. Journal of Politics, 59(2): 393–417. [Crossref], [Web of Science ®] , [Google Scholar]), Gates et al. (1996 Gates, Scott, Knutsen, Torbjørn L. and Moses, Jonathon W. 1996. Democracy and peace: a more skeptical view. Journal of Peace Research, 33(1): 1–10. [Crossref], [Web of Science ®] , [Google Scholar]), Gowa (1995 Gowa, Joanne. 1995. Democratic states and international disputes. International Organization, 49(3): 511–22. [Crossref], [Web of Science ®] , [Google Scholar]), Kegley and Hermann (1999 Kegley, Charles W. and Hermann, Margaret R. 1999. Putting military intervention into the democratic peace: a research note. Comparative Political Studies, 30(1): 78–107. [Crossref] , [Google Scholar]), Layne (1994 Layne, Christopher. 1994. Kant or cant: the myth of the democratic peace. International Security, 19(2): 5–49. [Crossref], [Web of Science ®] , [Google Scholar]), Mearsheimer (1990 Mearsheimer, John J. 1990. Back to the future: instability in Europe after the cold war. International Security, 15(1): 5–56. [Crossref], [Web of Science ®] , [Google Scholar]), Rosato (2003 Rosato, Sebastian. 2003. The flawed logic of democratic peace theory. American Political Science Review, 97(4): 585–602. [Crossref], [Web of Science ®] , [Google Scholar]), Spiro (1994 Spiro, David E. 1994. The insignificance of the liberal peace. International Security, 19(2): 50–86. [Crossref], [Web of Science ®] , [Google Scholar]) and Thompson (1996 Thompson, William R. 1996. Democracy and peace: putting the cart before the horse?. International Organization, 50(1): 141–74. [Crossref], [Web of Science ®] , [Google Scholar]). On how, in the Lakatosian sense, ‘realism and/or neorealism has been “falsified”’, see Ray (2003: 241).

Anglosphere United? Examining and Explaining 20th Century War Time Alliances in the English Speaking World

Throughout the 20th century the major powers in the global Anglosphere often found themselves allies in armed conflict. These war-time alliances – sometimes temporary, more often part of a longer term cooperation – are sometimes held to arise because of common histories, common values, similar national ideologies and similar notions of international right and wrong. Indeed, the political rhetoric surrounding declarations of war has often cited such factors as colonial history, international friendship and “special relationships” as motivators for joining armed coalitions against third party states. Yet while there stand stark examples of these major English speaking powers acting entirely in congress there exist numerous instances where one or more of these powers chose not to join a coalition alongside their Anglophonic associates. This paper argues that explanations of Anglophonic coalitions that rely on notions of a shared history, similar political ideologies, common political and social values or similar notions of international morality all fall short of explaining the coalition joining/rejecting behaviour of the major powers of the Anglosphere in war-time during the 20th century. Drawing on data from the Correlates of War (CoW) project, this paper will show that pure national interest drove the decisions of states to join or reject coalitions, lending strong support to a structural realist explanation for their behaviour.

I Don’t Get No Respect:1 The Travails of IPE2

The question of whether IPE journals are boring, in Benjamin Cohen's provocative words, provides us with a useful opportunity to introspect on the state of the field. Briefly, to set the stage, Cohen argues that IPE has begun to mimic the methodological approach of most of the economics field—leading to a focus on mid-level theory—rather than on the big picture that characterized IPE in the early 1970s and 1980s. Cohen argues that journal editors have an important role to play to rectify this lack of imaginative thinking and writing. Specifically, he develops three well-articulated solutions. First, he suggests that the field would benefit from more review essays and that editors should actively solicit such articles. Second, he argues that symposia on various themes could help spice up the debate in the field. And third, he notes that changing submission policies to encourage commentaries and provocative arguments would enhance the prospects for greater creativity. One might simply dismiss these concerns about the obsession with quantitative techniques and large data sets as just another fad. After all, much of political science (particularly the study of international conflict) was dominated by the “scientific” approach to studying conflict in the 1970s. UN voting studies are an example of obsession with quantification. The Correlates of War (COW) data set and analysis are the most prominent exemplars of this phenomenon in conflict studies. Since then, COW data has been extensively used, but at the same time, there has been backlash against the original statistical approaches. Many alternatives, including formal modeling, qualitative techniques, and critical security studies, among others, have been developed to overcome what was often seen as “mindless number crunching.” So maybe it is just a matter of time before the pendulum swings back. This symposium might then be seen as an effort to give …

Does Conflict Disrupt Growth? Evidence of the Relationship between Political Instability and National Economic Performance

Current empirical growth models limit the determinants of country growth to geographic, economic, and institutional variables. This study draws on conflict variables from the Correlates of War (COW) project to ask a critical question: How do different types of conflict affect country growth rates? It finds that wars slow the economy. Estimates indicate that civil war reduces annual growth by .01 to .13 percentage points, and high-intensity interstate conflict reduces annual growth by .18 to 2.77 percentage points. On the other hand, low-intensity conflict slows growth much less than high-intensity conflict, and may slightly increase it. The detrimental effect of conflict on growth is intensified when examining non-democracies, low income countries, and countries in Africa.

Trading Data

Some scholars have rushed to judgment about the nature of the relationship between trade and conflict, making strong assumptions about the data upon which their conclusions rest. In this paper, we test these assumptions, showing that they are often not warranted and, thus, pose threats to many of our conclusions about trade’s impact on conflict. We discuss official trade statistics; the treatment of missing trade data; and problems with some decision rules being adopted within our research community. We introduce the new Correlates of War (COW) Trade Data Set; discuss the rationale behind our coding decisions; and compare this data set with other sets. The end result is a series of findings that should help our field advance its understanding of the often difficult issue of trade’s relationship with international conflict.

The Long-Run Dynamic of the Nexus between Military Strength and National Power: An Econometric Analysis

A number of literatures suggest that military strength has been losing centrality and importance to nonmilitary factors of national power. In this paper, logistic regressions and data from the Correlates of War (COW) project are used to investigate whether over the 1820–2000 time horizon, for the great powers and their proximate contenders, the importance of military capabilities to national power has declined vis-à-vis that of economic capabilities. Estimation was carried out using generalized estimating equations (GEEs). The overall picture that emerges from the analysis is that of a transition in progress from a systemic state in which military capabilities were the dominant determinants of national power to a state in which economic capabilities will become the dominant ones. The analysis is concerned with long-run trends, and its results are not necessarily applicable to specific countries and circumstances.

The Declining Risk of Death in Battle

A recent article using the new Correlates of War (COW) data on the distribution of interstate, intrastate, and extrastate wars from 1816 to 1997 claims there was a relatively constant risk of death in battle during that time. We show that the authors' information is skewed by irregularities in the COW deaths data, and contest their pessimistic interpretation. Using revised information on battle deaths from 1900 to 2002 we demonstrate that the risk of death in battle by no means followed a flat line, but rather declined significantly after World War II and again after the end of the Cold War. Future users should note that the deaths data collected for the three conflict types by COW are not comparable, and using them as such tends to underestimate the share of fatalities due to major interstate conflicts.

Alliances, Armed Conflict, and Cooperation: Theoretical Approaches and Empirical Evidence

Alliances are subject to many scholarly inquiries in international relations and peace research because they are major instruments of foreign and security policies. Since the early work on alliances produced by the Correlates of War (COW) project, there have been significant advances in conceptual, theoretical, and empirical alliance research. New typologies and data permit us to differentiate more thoroughly among a variety of alliance objectives and functions. Furthermore, there has been new theoretical and empirical research on alliance formation, alliance configuration/polarization, effects of alliances on military conflict, connections between alliances and trade, and the economics of alliances. Providing new theoretical approaches, data, and empirical evidence on alliances, this special issue includes articles that address alliance formation, alliance polarization, alliances and democratization, trade among allies, regional economic institutions with alliance obligations, and defense industrial policies of military alliances. The articles in this issue extend our understanding of alliances past the traditional realist balance-of-power framework and encourage further testing and refinement of older alliance arguments and extensions to new theoretical developments.

A Revised List of Wars Between and Within Independent States, 1816-2002

Gleditsch and Ward (1999) examined the criteria for membership in the international system employed by the Correlates of War (COW) project and developed a revised list of independent nation states since 1816. These revisions in turn have implications for other datasets based on the COW system membership classification. This article suggests various revisions to the COW project’s list of wars to create a dataset compatible with the revised list of independent states. It identifies additional wars that qualify as interstate or civil wars as well as additional participating states to these wars. I show how the COW project’s criteria, based on recognition by France and the UK to identify states as system members in the Nineteenth century and early Twentieth century, understate the total amount of conflict between and within the independent states identified by the Gleditsch and Ward list. An appendix to the article displays a revised list of wars since 1816, with updates for 1997 to 2002 based on data compiled by the Department of Peace and Conflict Research at Uppsala University, and details several changes to the current release of the COW war data over the previous 1994 ICPSR release. The article concludes by outlining an agenda for future collection and improvement of data on wars.

The Correlates of War Project: a Bibliographic History of the Scientific Study of War and Peace, 1964-2000

The Correlates of War (COW) project is a unique research project that has been central to the world politics research community for thirty-six years. Since its founding by J. David Singer at the University of Michigan in 1964, the project has contributed significantly to the scientific study of war and conflict. In this article, we provide a historical summary of the COW research program through a selected bibliography of its published scholarship in four stages from 1964 to 2000.