Medellin's government wanted to raise its efficacy, legitimacy, and control. The city identified 80 neighborhoods with weak state presence and competing armed actors. In half, they increased non-police street presence tenfold for two years, offering social services and dispute resolution. In...

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...

Most countries in the periphery specialized in the export of just a handful of primary products for most of their history. Some of these commodities have been more volatile than others, and those with more volatile prices have grown slowly relative both to the industrial leaders and to other...

The contending fundamental determinants of growth -- institutions, geography and culture --exhibit far more persistence than do the growth rates they are supposed to explain. So, what exogenous shocks might account for the variance around those persistent fundamentals? The terms of trade seems...

In 2008, Uganda granted hundreds of small groups $400/person to help members start individual skilled trades. Four years on, an experimental evaluation found grants raised earnings by 38% (Blattman, Fiala, Martinez 2014). We return after 9 years to find these start-up grants acted more as a...

As low-income countries industrialize, workers choose between informal self-employment and low-skill manufacturing. What do workers trade off, and what are the long run impacts of this occupational choice? Self-employment is thought to be volatile and risky, but to provide autonomy and...

In the past decade, nearly 20 studies have found a strong, persistent pattern in surveys and behavioral experiments from over 40 countries: individual exposure to war violence tends to increase social cooperation at the local level, including community participation and prosocial behavior. Thus...

States and aid agencies use employment programs to rehabilitate high-risk men in the belief that peaceful work opportunities will deter them from crime and violence. Rigorous evidence is rare. We experimentally evaluate a program of agricultural training, capital inputs, and counseling for...

Most nations have experienced an internal armed conflict since 1960. The past decade has witnessed an explosion of research into the causes and consequences of civil wars, belatedly bringing the topic into the economics mainstream. This article critically reviews this interdisciplinary...

We study two interventions for underemployed youth across five Ethiopian sites: a $300 grant to spur self-employment, and a job offer to an industrial firm. Despite significant impacts on occupational choice, income, and health in the first year, after five years we see nearly complete...