As in many cities, gangs in Medellín provide order and collect 'taxes'. Why do gangs govern civilians? Some argue that criminal and state rule are substitutes. Hence, increasing state presence should crowd out gangs. But they could also be complements. States produce growth and general demand...

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...

In 2016 the city of Bogotá doubled police patrols and intensified city services on high-crime streets. They did so based on a policy and criminological consensus that such place-based programs not only decrease crime, but also have positive spillovers to nearby streets. To test this, we worked...

Cities target police patrols and public services to control crime. What are the direct and spillover effects of such targeted state services? In 2016 the city of Bogotá, Colombia, experimented on an unprecedented scale. They randomly assigned 1,919 streets to either 8 months of doubled police...

For citizens across Latin America, basic order is provided by local criminal organizations. Existing studies establish that criminal governance is pervasive, persistent, and consequential --- not only for those governed but for macro-level political, social, and economic outcomes. Yet systematic...

The paper shows that self-control, time preferences, and values are malleable in adults, and that investments in these skills and preferences reduce crime and violence. The authors recruited criminally-engaged Liberian men and randomized half to eight weeks of group cognitive behavioral therapy,...

In this paper I advance an explanation of the social origins of cocaine trafficking in Colombia in which two thresholds are distinguish. The first threshold occurs when the knowledge and the willingness for a specific criminal activity reproduce faster than the enforcement capacity of the...

We study the effects of broken windows policing on crime using geo-located crime and arrest reports for 80 Colombian cities. Broadly defined, broken windows policing consists of intensifying arrests - sometimes for minor offenses - to deter potential criminals. To estimate causal effects, we...

Test direct, spillover and aggregate effects of hot spots policing on crime in a high crime environment. Methods: We identified 967 hot spot street segments and randomly assigned 384 to a six-months increase in police patrols. To account for the complications resulting from a large experimental...

We investigate if there is any effect on crime following the installation of public surveillance cameras. To do so, we benefit from a quasi-experiment that took place in Medellin, Colombia with the installation of 587 cameras between 2013 and 2015. We highlight three main findings. First, there...