We conducted a laboratory experiment to test the comparative statics predictions of a new approach to collective action games based on the method of stability sets. We find robust support for the main theoretical predictions. As we increase the payoff of a successful collective action (accruing...

We study a standard collective action problem in which successful achievement of a group interest requires costly participation by some fraction of its members. How should we model the internal organization of these groups when there is asymmetric information about the preferences of their...

Illegal arms are responsible for thousands of deaths in civil wars every year. Yet, their trade is very hard to detect. We propose a method to statistically detect illegal arms trade based on the investor knowledge embedded in financial markets. We focus on eight countries under UN arms embargo...

Gun buyback programs (GBPs), which use public funds to purchase civilians' privately-owned firearms, aim to reduce gun violence. However, little is known about their effects on firearm-related crime or deaths. Using data from the National Incident Based Reporting System, we find no evidence that...

Landmine contamination affects the lives of millions in many conflict-ridden countries long after the cessation of hostilities. Yet, little research exists on its impact on post-conflict recovery. In this study, we explore the economic consequences of landmine clearance in Mozambique, the only...

A central authority possessing tax and expenditure responsibilities can readily provide an efficient level of a public good. Absent a central authority, voluntary arrangements must replace coercive ones. Significant under-provision must be expected. International public goods are particularly...

In social and economic networks linked agents often share additional links in common. There are two competing explanations for this phenomenon. First, agents may have a structural taste for transitive links -- the returns to linking may be higher if two agents share links in common. Second,...

We analyze the economic determinants and effects of prior appropriation water rights that were voluntarily implemented across an immense area of the US West, abruptly replacing common-law riparian water rights. At the same time and place, vast private irrigation infrastructure added to the US...

In this paper, we use mobile messaging to leverage recipients' social ties and encourage offline prosocial activities in groups. In particular, we conduct a randomized field experiment with 80,000 blood donors and study how behavioral interventions and economic rewards motivate offline group...

We show that extremely poor, war-affected women in northern Uganda have high returns to a package of $150 cash, five days of business skills training, and ongoing supervision. 16 months after grants, participants doubled their microenterprise ownership and incomes, mainly from petty trading. We...