Peace and regime type can be examined at the dyadic, nation, and system levels. At the dyadic level, it is well established that democracies rarely if ever fight each other. At the national level, the broad consensus is that there is no significant relationship between democracy and war...

Countries have better abilities and stronger incentives to engage in militarized conflicts the larger and more powerful they are. The article applies Zipf's notion of a ``gravity model'' to the risk of interstate conflict and argues that the empirical relationship between size and distance and...

A measure—trade efficiency—that models the extent to which individual economic entities within two countries trade with each other is used to investigate the claim that symmetrical dependence on trade between two states is required for the trade bond to reduce the probability of...

This article examines the link between subnational poverty and the location of civil war events. Drawing on the ACLED dataset, which breaks internal conflicts down to individual events at the local level, we take a disaggregated approach to the study of conflict. Local-level socioeconomic data...

This article introduces the Polity IIId (“d†is for dates) data set. The Polity IIId project codes the precise dates of changes in political structure identified by Polity III for all independent countries in the international system from 1800 to 1994. By moving from annual...

In the literature on civil war onset, several empirical results are not robust or replicable across studies. Studies use different definitions of civil war and analyze different time periods, so readers cannot easily determine if differences in empirical results are due to those factors or if...