The Pro-Social Motivations of Police Officers (draft)

• with Felipe Goncalves
• How do public sector workers balance their pro-social motivations with private interests? In this study of police officers, we exploit two institutional features that change the implicit cost of making an arrest: arrests near the end of an officer's shift are more likely to require overtime work, and arrests made on days when an officer "moonlights'' at an off-duty job after their shift have a higher opportunity cost. We document two consequences for officer behavior. First, contrary to popular wisdom, officers reduce arrests near the end of their shift, and the quality of arrests increases. We argue that these patterns are driven by officer preferences rather than departmental policy, fatigue, or incapacitation from earlier arrests. Second, officers further reduce late-shift arrests on days in which they moonlight after work, suggesting that they are, in fact, modestly responsive to financial incentives. Using these results, we estimate a dynamic model that identifies officers' implied tradeoff between private and pro-social motivations. We find that police officers exhibit high pro-social motivation towards their arrest activity. In contrast to prior research showing that law enforcement outcomes are sensitive to financial incentives at an institutional level, incentives created by overtime pay are insufficiently large to appreciably change police decision-making at the margin.

Police Force Size and Civilian Race (draft)

• with Ben Hansen, Emily Weisburst and Morgan Williams
• Conditionally accepted, American Economic Review: Insights
• We report the first empirical estimate of the race-specific effects of larger police forces in the United States. Each additional police officer abates approximately 0.1 homicides. In per capita terms, effects are twice as large for Black versus white victims. At the same time, larger police forces make more arrests for low-level “quality-of-life” offenses, with effects that imply a disproportionate burden for Black Americans. Notably, cities with large Black populations do not share equally in the benefits of investments in police manpower. Our results provide novel empirical support for the popular narrative that Black communities are simultaneously over and under-policed.

Can Precision Policing Reduce Gun Violence? Evidence from "Gang Takedowns" in New York City (draft)

• with Mike LaForest and Jacob Kaplan
• Conditionally accepted, Journal of Policy Analysis & Management
• During the last decade, while national homicide rates have remained flat, New York City has experienced a second great crime decline, with gun violence declining by more than 50 percent since 2011.  In this paper, we investigate one potential explanation for this dramatic and unexpected improvement in public safety -- the New York Police Department's shift to a more surgical form of "precision policing”, in which law enforcement focuses resources on a small number of individuals who are thought to be the primary drivers of violence.  We study New York City's campaign of "gang takedowns" in which suspected members of criminal gangs were arrested in highly coordinated raids and prosecuted on conspiracy charges. We show that gun violence in and around public housing communities fell by approximately 30 percent in the first year after a gang takedown.  Our estimates imply that these coordinated gang takedowns explain nearly one quarter of the decline in gun violence in New York City's public housing communities over the last eight years.

How Many Complaints Against Police Officers Can Be Abated By Incapacitating a Few "Bad Apples?" (draft)

• with Jacob Kaplan
• Conditionally accepted, Criminology & Public Policy
• The notion that the unjustified use of force by police officers is concentrated amongst a few “bad apples” is a popular descriptor which has gained traction in scholarly research and achieved considerable influence among policymakers. But is removing the bad apples likely to have an appreciable effect on police misconduct? Leveraging a simple policy simulation and data from the Chicago Police Department, we estimate that removing the top 10 percent of officers identified based on ex ante risk and replacing them with officers drawn from the middle of the risk distribution would have led to only a 6 percent reduction in use of force incidents in Chicago over a ten-year period.  Our analysis suggests that surgically removing predictably problematic police officers is unlikely to have a large impact on citizen complaints. By assembling some of the first empirical evidence on the likely magnitude of incapacitation effects, we provide critical support for the idea that early warning systems must be designed, above all, to deter problematic behavior and promote accountability.

The Minimum Legal Drinking Age and Crime Victimization  (draft) (NBER working paper #26051)

• with Ben Hansen and Rachel Ryley
• Revise & Re-submit, Journal of Human Resources
• For every crime there is a victim. However nearly all studies in the economics of crime have focused the causal determinants of criminality.  We present novel evidence on the causal determinants of victimization, focusing on legal access to alcohol.  The social costs of alcohol use and abuse are sizable and well-documented.  We find criminal victimization - for both violent and property crimes - increases noticeably at age 21. Effects are not present at other birthdays and do not appear to be driven by a birthday "celebration effect." The effects are particularly large for sexual assaults, especially those that occur in public locations.  Our results suggest prior research which has focused on criminality has understated the true social costs associated with increased access to alcohol. 

Street Light Outages, Public Safety and Crime Attraction (draft)

• with Jacob Kaplan and Mike LaForest
• Revise & Re-submit, Journal of Quantitative Criminology
•  For more than one hundred years, street lighting has been one of the most ubiquitous capital investments in public safety. Prior research on street lighting is largely limited to ecological studies of very small geographic areas, creating substantial challenges with respect to both causal identification and statistical power. In this study, we provide a comprehensive examination of the effect of street lighting on crime, leveraging a natural experiment created by the differential timing of the repair of nearly 300,000 street light outages in Chicago. By conditioning on street segment fixed effects and focusing on a short window of time around the repair of a street light outage, we can credibly rule out confounding factors due to area-specific time trends as well as street segment-level correlates of crime. We find that outdoor nighttime crimes change very little on street segments affected by street light outages, but that outages cause crime to spill over to nearby street segments. Effects are largest for robberies and motor vehicle theft. Despite strong environmental and social characteristics that tend to tie crime to place, we observe that street light outages are sufficiently salient to disrupt longstanding patterns and cause crime to follow patterns of human activity.  While the impact of localized street light outages can reverberate throughout a community, the findings imply that improvements in lighting can be defeated by the displacement of crime to adjacent spaces and therefore do not necessarily suggest that localized investments in municipal street lighting will yield a large public safety dividend.

Ambient Lighting, Use of Outdoor Spaces and Perceptions of Public Safety: Evidence from a Survey Experiment (draft)

• with Jacob Kaplan
• Revise & Re-submit, Security Journal
• Observational evidence suggests that better ambient lighting leads people to feel safer when spending time outdoors in their community.  We subject this finding to greater scrutiny and elaborate on the extent to which improvements in street lighting affect routine activities during nighttime hours.  We report evidence from a survey experiment that examines individuals' perceptions of safety under two different intensities of nighttime ambient lighting.  Brighter street lighting leads individuals to feel safer but poor lighting does not change people's willingness to spend time outdoors or to engage in behaviors which mitigate risk.  Over half of survey respondents are willing to pay an additional $400 per year in taxes in order to finance a hypothetical program which would replace dim yellow street lights with brighter LED lights.  Results suggests that street lighting is a means through which policymakers can control crime while also improving perceived well-being.

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COVID-19 Has Strengthened the Relationship Between Alcohol Consumption and Domestic Violence (draft) 

• with Shooshan Danagoulian and Monica Deza
• A large body of evidence documents a link between alcohol consumption and violence involving intimate partners and close family members. Recent scholarship suggests that since the onset of the COVID-19 pandemic and subsequent stay-at-home orders, there has been a marked increase in domestic violence. This research considers an important mechanism behind the increase in domestic violence during the COVID- 19 pandemic: an increase in the riskiness of alcohol consumption. We combine 911 call data with newly-available high-resolution microdata on visits to bars and liquor stores in Detroit, MI and find that the strength of the relationship between visits to alcohol outlets and domestic violence more than doubles starting in March 2020. We find more limited evidence with respect to non-domestic assaults, supporting our conclusion that it is not alcohol consumption per se but alcohol consumption at home that is a principal driver of domestic violence.