Our analysis melds two traditional approaches to promoting quality. The first is restoring the stock of quality. The second is curbing its flow of deterioration. Although both approaches are widely used in real world settings, analytic models have tended to focus on one strategy or the other. We...

We develop a dynamic theory of resource wars and study the conditions under which such wars can be prevented. The interaction between the scarcity of resources and the incentives for war in the presence of limited commitment is at the center of our theory. We show that a key parameter...

Governments fighting terrorists have many tactical options, yet these options often yield unintended and counterproductive consequences. This paper models a terrorist organization, a religious group from which the terrorists recruit suicide bombers, and the society in which the terrorists are...

We develop and test an economic theory of insurgency motivated by the informal literature and by recent military doctrine. We model a three-way contest between violent rebels, a government seeking to minimize violence by mixing service provision and coercion, and civilians deciding whether to...

Research on insurgency has been invigorated this past decade by better data, improved methods, and the urgency of understanding active engagements in Iraq and Afghanistan. This empiricists' insurgency reinforces a classic literature on the essential role of civilians while challenging older...

We use variation in exposure to victimization of 1,537 households of eastern Congo for each year of 1990-2013 to examine the formation of preferences to participate in armed groups. In this context, most armed groups are Congolese militia, whose objective is fighting foreign armed groups. We...

Mechanism design teaches us that a mediator can strictly improve the chances of peace between two opponents even when the mediator has no independent resources, is less informed than the two parties, and has no enforcement power. We test the theory in a lab experiment where two subjects...

Arid regions of Africa are expanding by thousands of square kilometers a year, potentially disturbing pastoral routes that have been forged over a long period of time. This disturbance is often said to explain why "herder-farmer" conflicts have erupted in recent years, as pastoralists and...

We use census data for the US, Canada, Spain, and UK to estimate bilateral migration rates to these countries from 25 Latin American and Caribbean nations over the period 1980 to 2005. Latin American migration to the US is responsive to labor supply shocks, as predicted by earlier changes in...

In recent years, cases in which state governments chose to override federal environmental regulation with tighter regulations of their own have become increasingly common, even for pollutants that have substantial spillovers across states. This paper argues that this change arose at least in...