Geographic and cross‐national variation in the frequency of intrastate armed conflict and
civil war is a subject of great interest. Previous theory on this variation has focused on the …

A fully revised edition of the classic reference on concepts and their role in social science
research Social Science Concepts and Measurement offers an updated look at the theory …

In the period 1946-2001, there were 225 armed conflicts and 34 of them were active in all of
or part of 2001. Armed conflict remains a serious problem in the post-Cold War period. For …

The Puzzle of Peace moves beyond defining peace as the absence of war and develops a
broader conceptualization and explanation for the increasing peacefulness of the …

This article presents new data on the start and end dates and the means of termination for
armed conflicts, 1946—2005. These data contribute to quantitative research on conflict …

Scholars for a long time theorized about the role of political leaders, but empirical research
has been limited by the lack of systematic data about individual leaders. Archigos is a new …

The concept of electoral competition is relevant to a variety of research agendas in political
science, yet the question of how to measure electoral competition has received little direct …

This article introduces the Alliance Treaty Obligations and Provisions (ATOP) dataset. We
begin by describing the rationale for collecting the ATOP data, its scope, and some general …

Scholars and observers of the international system often comment on the decreasing
importance of international boundaries as a result of the growth of international economic …

While territory, oil, and water are frequently mentioned as resources likely to promote
interstate conflict, diamonds have emerged as a prominent factor in explanations of civil war …