Reducing Crime Through Environmental Design: Evidence from a Randomized Experiment of Street Lighting in New York City (draft) (Probable Causation podcast)

• with Ben Hansen, Jason Lerner and Lucie Parker
• Revise & Re-Submit, Journal of Quantitative Criminology
• This paper offers the first experimental evidence of the effect of street lighting on crime. Through a unique public partnership between the New York City Mayor’s  Office of Criminal Justice, the New York City Police Department and the New York City Housing Authority, temporary street lights were randomly allocated to public housing developments from March through August 2016. We find evidence that communities that were assigned more lighting experienced sizable reductions in crime. After accounting for potential spatial spillovers, we find that the provision of street lights led, at a minimum, to a 36 percent reduction in serious outdoor crimes.  The pattern in our findings is most consistent with large general deterrence effects.

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.

​Measuring Marginal Crime Concentration: A New Solution to an Old Problem  (draft)

• ​with Jacob Kaplan and Maria Cuellar
• Accepted, Journal of Research in Crime and Delinquency
• In his 2014 Sutherland address to the American Society of Criminology, David Weisburd demonstrated that the share of crime that is accounted for by the most crime-ridden street segments is notably high and strikingly similar across cities, an empirical regularity referred to as the "law of crime concentration."  Using data from three of the largest cities in the United States, compare observed crime concentration to a counterfactual distribution of crimes generated by randomizing crimes to street segments. We show that this method avoids a key pitfall that causes a popular method of measuring crime concentration to overstate the degree of crime concentration in a city.  Most (but not all) crimes are concentrated amongst a small number of hot spots but the precise relationship is weaker -- sometimes considerably so -- than has been documented in the empirical literature. Within a city, crime is least concentrated in the neighborhoods that experience the largest number of crimes. The law of crime concentration sometimes holds only tenuously in the communities in which crimes are most prevalent.  The method we propose is simple and easily interpretable and compliments recent advances which use the Gini coefficient to measure crime concentration.

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. 

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

• with Mike LaForest and Jacob Kaplan
• 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 rapid shift from a policy of mass enforcement, characterized by the intensive use of street stops and field interrogations, 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.  In anticipation of a 2013 federal court ruling in which the NYPD's stop and frisk practices were found to be unconstitutional, the number of official street stops made by NYPD officers declined from a high of 680,000 in 2011 to just 12,000 just five years later.  During the same period, the NYPD dramatically increased its investment in a different tactic -- targeted enforcement actions against criminal gangs, often centered around the City’s public housing communities.  In this paper, 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.

Street Light Outages, Public Safety and Crime Displacement: Evidence from Chicago (draft)

• with Jacob Kaplan and Mike LaForest
• For more than one hundred years, street lighting has been one of the most ubiquitous and enduring 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 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 street light outages cause crime to spill over to nearby street segments. Effects are largest for robberies and motor vehicle theft, two common street crimes which have been thought to be most sensitive to changes in ambient lighting. These findings suggest that crime may follow patterns of human activity and that the impact of localized street light outages can reverberate throughout a community.

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

• with Jacob Kaplan
• Revise & Re-submit, 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.

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

• with Jacob Kaplan
• 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.

Testing Public Policy at the Frontier: The Effect of the $15 Minimum Wage on Public Safety in Seattle (draft)

• with David Mitre Becerril​
• Revise & Re-submit, Criminology & Public Policy
• In 2017, Seattle, Washington, became the first city in the United States to increase its minimum wage to $15 per hour, more than double the federal minimum wage. Not only was a $15 minimum wage unprecedented, but the increase was also extremely rapid, with the minimum wage rising by nearly 60 percent in just two years. Using a synthetic differences-in-differences estimator, we consider the impact of Seattle's landmark minimum wage legislation on public safety.  While there is speculative evidence for an increase in commercial burglaries, we find little evidence that Seattle experienced a change in its aggregate rate of violent or property offending relative to other U.S. cities. To better understand the mechanisms underlying our findings, we investigate the impacts of the local wage law on employment and earnings for Seattle's low-skilled labor market. We detect no meaningful adverse effects on the employment rates of low-wage workers.  

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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.