Limiting aggressive policing can reduce police and civilian violence
World Development, 2022: 105961, p. 1-18.

Abstract Governments in the Americas rely on aggressive policing tactics to fight crime, despite scant evidence of impact. While recent studies depict militarized policing as a driver of violence, few governments have reconsidered their use of it. What impact does a restriction on aggressive policing have on violence, and why? This paper examines limits on police use of force and how they can be implemented to reduce both police and civilian violence. I argue that reforms that require internal, non-police oversight can be effective institutional constraints, minimizing police violence. In settings where organized crime is widespread, these limits can have spillover effects and further decrease civilian violence by (1) slowing the territorial diffusion of criminal conflict and (2) making conflict more predictable. I test these claims by examining an abrupt limit on police raids in Rio de Janeiro, Brazil. I find that limiting raids – militarized police strikes targeting criminal gangs and communities under their control – led to a 66% decrease in police killings and a 58% decrease in homicides. The effects were concentrated in police precincts where rival criminal groups are in close proximity. Limiting raids did not lead police to be more violent during ordinary patrolling duties, and did not affect property crimes. The implication is that restraining police use of force in high-violence settings may save lives and be no worse than hard-on-crime strategies.

How do Covid-19 stay-at-home restrictions affect crime? Evidence from Rio de Janeiro, Brazil
EconomiA, 2022: 147-163. (with Ana Paula Pellegrino).

Abstract How do changes in mobility impact crime? Using police precinct-level daily crime statistics and shootings data from the state of Rio de Janeiro, Brazil, we estimate that extortion, theft, and robberies decrease by at least 41.6% following COVID-19 mandated stay-at-home orders and changes in mobility in March 2020. Conversely, we find no change in violent crimes, despite fewer people being on the streets. To address the relationship between crime and mobility, we use cellphone data and split the precincts into subgroups by pre-Covid-19-related restrictions mobility quintiles. We estimate a similar average decrease in extortion regardless of a precinct’s previous activity level, but find that the decrease in theft and robberies is substantially higher for the more mobile precincts while it disappears for the least mobile precincts. Using daily cellphone mobility data aggregated at the police precinct level, we find that changes in mobility while the stay-at-home order is in place only have a meaningful effect on robberies, which increase in likelihood when a precinct’s mobility ranking is higher than the previous day. Together, these results suggest that the stay-at-home order and associated decline in mobility strongly affected extortion and property crimes while not interfering with the dynamics of violent crime. These findings support the hypothesis that violent and property crime follow different dynamics, particularly where there is a bigger impact of organized criminal groups.