Temporal dynamics and heterogeneity in the quantitative study of international conflict

Our discussion focuses on the importance of temporal dynamics in the study of international conflict and more specifically on the nature of those dynamics as they relate to interdependence. Our goal is to point out some areas in which the substantial achievements of international politics scholars may be further improved. In part because of the unique challenges posed by data on international relations, students of international politics have been among those at the forefront of developing innovative approaches to the study of political phenomena. For example, scholars studying international conflict have, in recent years, begun to go beyond the mere incidence of international disputes to study the process by which conflicts occur, including the stages through which nations typically pass as crises escalate to war (e.g., Reed 2000b; Reed and Clark 2000; Reed and Lemke 2001; Schultz 2000, 2001; Signorino 1999; Smith 1996, 1999) or fail to escalate to war (Gartzke this volume; Manseld this volume). Such studies highlight a central characteristic of international conflict: The importance of time and temporal dynamics in the development of such disputes. These studies have been accompanied by ever more sophisticated analyses of the causes of conflict, many of which explicitly model the influence of those causes over time (e.g., Beck, Katz, and Tucker 1998; Beck 1999; Bennett and Stam 2000; Maoz and Russett 1993; Oneal and Russett 1999a, 1999b). We emphasize the importance of paying greater attention to the connection between a number of general theoretical expectations regarding time and conflict and the kinds of statistical tools used to model and test those expectations. Neither model assumptions (e.g., that of temporal parameter stability) nor basic political facts about the phenomenon of study (e.g., the repeated nature of conflict in the international arena) are innocuous. Different methodological treatments of repeated disputes, for example, imply fundamentally different understandings of the effects of those disputes on current conflicts. We concentrate on three main areas ripe for development: investigating temporal variation in the influence of covariates on conflict, evaluating the importance of repeated conflicts between nations over time, and incorporating corrections for unobserved heterogeneity (both temporal and otherwise) in international-conflict data.