Why does illegal trade often flourish without formal enforcement, but sometimes fail? Why do illegal trade-reducing policies often fail? Why do States often appear to tolerate illegal trade? A model of trade with cops and robbers provides answers. `Safety in numbers' is a key element: the...

Black markets are estimated to represent a fifth of global economic activity, but their response to policy is poorly understood because participants systematically hide their actions. It is widely hypothesized that relaxing trade bans in illegal goods allows legal supplies to competitively...

Canonical models of crime emphasize economic incentives. Yet, causal evidence of sorting into criminal occupations in response to individual-level variation in incentives is limited. We link administrative socioeconomic microdata with the universe of arrests in Medellín over a decade. We...

Gangs govern millions worldwide. Why rule? And how do they respond to states? Many argue that criminal rule provides protection when states do not, and that increasing state services could crowd gangs out. We began by interviewing leaders from 30 criminal groups in Medellin. The conventional...

We investigate how criminal organizations strategically use violence to influence elections in order to get captured politicians elected. The model offers novel testable implications about the use of pre-electoral violence under different types of electoral systems and different degrees of...

Adequate wages are an important tool to shield public officials from special interests and corruption. But what is the equilibrium effect of higher wages in the presence of criminal pressure groups, who use both bribes and violence? By means of a regression discontinuity design, we show that an...

Mutual causation of predation and trade induces novel effects of commercial policy in this paper. The model can explain trade volume responses to market widening initiatives that are otherwise puzzlingly 'too big' or 'too small'. Efficient commercial policy (broadly defined) depends crucially on...

In the 16th century, North America contained 25-30 million buffalo; by the late 19th century less than 100 remained. While removing the buffalo east of the Mississippi took settlers over 100 years, the remaining 10 to 15 million buffalo on the Great Plains were killed in a punctuated slaughter...