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...

This paper conducts the first analysis of the effect of armed conflict on progress in meeting the United Nation’s Millennium Development Goals. We also examine the effect of conflict on economic growth. Conflict has clear detrimental effects on the reduction of poverty and hunger, on primary...

According to the liberal peace proposition, pairs of democratic states and pairs of states with extensive trade ties are more peaceful than other pairs of states, and democratic states are also more peaceful internally than other regime types. This article reviews the recent literature on the...

Dorussen (1999) concludes that trade between states reduces the incentives for conflict, but that the effect of trade diminishes with a larger number of countries. I demonstrate that the indicator Dorussen uses to gauge the impact of trade is dependent on the size of the system itself, and...

Esteban & Ray formalize the argument that conflict is likely to be more intense when individuals in a society are divided into two clearly identifiable groups where differences within groups are considerably smaller than differences between groups. They show that such polarization increases...

The article reviews the literature on the relationship between democracy and armed conflict, internal as well as interstate. The review points to several similarities between how democratic institutions affect both conflict types. It summarizes the main empirical findings and discusses the most...

An important key to reducing the suffering due to civil war is to shorten conflicts. The marked decrease in the incidence of conflicts in the 1990s was mostly due to a high number of conflict terminations, not to a decrease in the number of new wars. The articles in this special issue treat...

In this article, we re-examine the statistical evidence for the democratic peace at the dyadic level. We also investigate the seeming paradox that democracies are engaged in war as often as autocracies at the nation level. From the extensive literature on democracy and peace we have selected as...

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...