Crime Scenes

Kevin Lewis

January 13, 2021

Triple Disadvantage: Neighborhood Networks of Everyday Urban Mobility and Violence in U.S. Cities
Brian Levy, Nolan Phillips & Robert Sampson
American Sociological Review, December 2020, Pages 925-956


This article develops and assesses the concept of triple neighborhood disadvantage. We argue that a neighborhood's well-being depends not only on its own socioeconomic conditions but also on the conditions of neighborhoods its residents visit and are visited by, connections that form through networks of everyday urban mobility. We construct measures of mobility-based disadvantage using geocoded patterns of movement estimated from hundreds of millions of tweets sent by nearly 400,000 Twitter users over 18 months. Analyzing nearly 32,000 neighborhoods and 9,700 homicides in 37 of the largest U.S. cities, we show that neighborhood triple disadvantage independently predicts homicides, adjusting for traditional neighborhood correlates of violence, spatial proximity to disadvantage, prior homicides, and city fixed effects. Not only is triple disadvantage a stronger predictor than traditional measures, it accounts for a sizable portion of the association between residential neighborhood disadvantage and homicides. In turn, potential mechanisms such as neighborhood drug activity, interpersonal friction, and gun crime prevalence account for much of the association between triple disadvantage and homicides. These findings implicate structural mobility patterns as an important source of triple (dis)advantage for neighborhoods and have implications for a broad range of phenomena beyond crime, including community capacity, gentrification, transmission in a pandemic, and racial inequality.

The Ineffectiveness of 'Observe and Report' Patrols on Crime
Marco Fabbri & Jonathan Klick
International Review of Law and Economics, forthcoming


The deterrence effect of police on crime has been well established using modern quasi-experimental micro-econometric methods. Although the results from these studies uniformly suggest that police spending is cost justified, it is worth exploring whether police-like alternatives can deter crime even more cheaply. Unarmed private security personnel that conspicuously patrol a neighborhood have the potential to cheaply leverage the ability of police to be informed of crimes while also providing direct deterrence on their own. In the Fall of 2013, a neighborhood in Oakland, CA mounted a campaign to provide observe and report security patrols to augment the publicly provided policing in the area. While the initial effect of the additional security was a drop in crime, it quickly evaporated, calling into question the value of security forces that do not have the ability to apprehend criminals directly.


Counterevidence of crime-reduction effects from federal grants of military equipment to local police
Anna Gunderson et al.
Nature Human Behaviour, forthcoming


In 2017, the Trump Administration restored local law enforcement agencies' access to military weapons and some other types of surplus military equipment (SME) that had been prohibited by the Obama Administration. The Justice Department background paper used to justify this decision cited two papers published by the American Economic Association. These papers used SME data collected with a 2014 Freedom of Information Act request and concluded that SME, supplied to local law enforcement by the federal government via the 1033 Program, reduces crime. Here we show that the findings of these studies are not credible due to problems with the data. Using more detailed audit data on 1033 SME, we show that the 2014 data are flawed and that the more recent data provide no evidence that 1033 SME reduces crime.

Police demilitarization and violent crime
Kenneth Lowande
Nature Human Behaviour, forthcoming


Policymakers and advocates make contradictory claims about the effects of providing military equipment to local law enforcement, but this intervention is not well understood because of severe data limitations and inferential challenges. I use 3.8 million archived inventory records to estimate the magnitude of sources of bias in existing studies of the 1033 Program. I show that most variation in militarization comes from previously unobserved sources, which implies that studies that show crime-reduction benefits are unreliable. I then leverage recent policy changes to evaluate the effect of military equipment: the Obama Administration recalled property under Executive Order 13688, which resulted in a forced demilitarization of several hundred departments. Difference-in-difference estimates of agencies that retained similar equipment show negligible or undetectable impacts on violent crime or officer safety. These findings do not suggest that similar scale federal reforms designed to demilitarize police would have the downside risks proposed by proponents of military transfers.

Collars for Dollars: Arrests and Police Overtime
Aaron Chalfin & Felipe Goncalves
University of Pennsylvania Working Paper, October 2020


How do public sector workers balance pro-social motivations with private interests? In this study of police officers, an arrest often requires working overtime. We document two consequences to officer behavior. First, contrary to popular wisdom, officers reduce arrests near the end of their shift, and the quality of arrests increases. Second, officers further reduce late-shift arrests on days in which they "moonlight" after work. Using these results, we estimate a dynamic model that identifies officers' implied tradeoff between private and pro-social motivations. Incentives created by overtime pay are insufficiently large to change police decision-making at the margin.

Trauma at School: The Impacts of Shootings on Students' Human Capital and Economic Outcomes
Marika Cabral et al.
NBER Working Paper, December 2020


A growing number of American children are exposed to gun violence at their schools, but little is known about the impacts of this exposure on their human capital attainment and economic well-being. This paper studies the causal effects of exposure to shootings at schools on children's educational and economic outcomes, using individual-level longitudinal administrative data from Texas. We analyze the universe of shootings at Texas public schools that occurred between 1995 and 2016, and match schools that experienced shootings with observationally similar control schools in other districts. We use difference-in-differences models that leverage within-individual and across-cohort variation in shooting exposure within matched school groups to estimate the short- and long-run impacts of shootings on students attending these schools at the time of the shooting. We find that shooting-exposed students have an increased absence rate and are more likely to be chronically absent and repeat a grade in the two years following the event. We also find adverse long-term impacts on the likelihood of high school graduation, college enrollment and graduation, as well as employment and earnings at ages 24-26. Heterogeneity analyses by student and school characteristics indicate that the detrimental impacts of shootings are universal, with most sub-groups being affected.

Measuring the Direct and Spillover Effects of Body Worn Cameras on the Civility of Police-Citizen Encounters and Police Work Activities
Anthony Braga et al.
Journal of Quantitative Criminology, December 2020, Pages 851-876

Methods: This study assesses the direct effects of BWCs on citizen complaints, police use of force, and police proactivity and discretion during a 1-year randomized controlled trial in the Boston Police Department. Through a simultaneous quasi-experimental design, this study also investigates whether BWC deployment results in spillover effects onto control officers in treated districts as compared to comparison officers in untreated districts.

Results: Findings indicate that the use of BWCs reduces citizen complaints and police use of force but has no appreciable impact on officer activity or discretion. Furthermore, results indicate significant spillover reductions in citizen complaints for control officers in treated districts.

The effects of body-worn cameras on police-citizen encounters and police activity: Evaluation of a pilot implementation in Philadelphia, PA
Elizabeth Groff, Cory Haberman & Jennifer Wood
Journal of Experimental Criminology, December 2020, Pages 463-480

Methods: A quasi-experimental approach was used to examine the initial implementation of body-worn cameras (BWCs) in one district. This provided the opportunity for a natural experiment comparing officers in the district that deployed cameras with officers in three similar districts where no BWCs were deployed. Propensity score matching (PSM) was used to match BWC officers with non-BWC officers.

Results: BWC officers had about 38.3% fewer use of force incidents than non-BWC officers with similar numbers of use of force incidents in the previous year. On average, BWC officers made 46.4% fewer pedestrian stops and 39.2% fewer arrests than non-BWC officers. Vehicle stops and citizen complaints had nonsignificant declines for BWC officers.

Police Use of Force and Injury: Multilevel Predictors of Physical Harm to Subjects and Officers
Matthew Hickman et al.
Police Quarterly, forthcoming


The police must on occasion use physical force and weapons in order to apprehend and control subjects and fulfil the police function. It is inevitable that some of these interactions will result in injuries to both subjects and officers, with a range of both tangible and intangible harms and costs. It is therefore important to study injuries related to the use of force with an eye toward identifying opportunities to minimize injury and reduce the harms and costs. Injuries to both subjects and officers were examined in a sample of more than 10,000 use of force incidents drawn from 81 agencies located in 8 states. In addition to describing injury rates across a broad spectrum of situational and agency characteristics, we present multilevel logistic regression models predicting subject and officer injury. Among key findings, we report that the likelihood of injury for both subjects and officers is lower when force incidents end quickly and with the minimal necessary superior level of force relative to subject resistance, and higher for both subjects and officers when subjects flee. At the agency level, we find that the likelihood of injury varies by agency size and type. Finally, we explored possible higher-level variation and found that agencies in the sample from Midwestern states (primarily Wisconsin) have substantially lower injury rates that appear to be associated with their less frequent use of weapons and greater reliance on low-level physical force tactics, as compared to agencies in the sample from Western and other states.

Wielding a gun increases judgments of others as holding guns: A randomized controlled trial
Jessica Witt, Jamie Parnes & Nathan Tenhundfeld
Cognitive Research, November 2020


The gun embodiment effect is the consequence caused by wielding a gun on judgments of whether others are also holding a gun. This effect could be responsible for real-world instances when police officers shoot an unarmed person because of the misperception that the person had a gun. The gun embodiment effect is an instance of embodied cognition for which a person's tool-augmented body affects their judgments. The replication crisis in psychology has raised concern about embodied cognition effects in particular, and the issue of low statistical power applies to the original research on the gun embodiment effect. Thus, the first step was to conduct a high-powered replication. We found a significant gun embodiment effect in participants' reaction times and in their proportion of correct responses, but not in signal detection measures of bias, as had been originally reported. To help prevent the gun embodiment effect from leading to fatal encounters, it would be useful to know whether individuals with certain traits are less prone to the effect and whether certain kinds of experiences help alleviate the effect. With the new and reliable measure of the gun embodiment effect, we tested for moderation by individual differences related to prior gun experience, attitudes, personality, and factors related to emotion regulation and impulsivity. Despite the variety of these measures, there was little evidence for moderation. The results were more consistent with the idea of the gun embodiment effect being a universal, fixed effect, than being a flexible, malleable effect.

Incarceration and Labor Market Conditions of the Underclass in the United States: An Empirical Investigation
Kerem Cantekin & Ceyhun Elgin
European Journal on Criminal Policy and Research, December 2020, Pages 529-546


In this paper using both annual time-series data at the federal level as well as annual state-level (balanced) panel data from 1980 to 2017 we investigate the relationship between several labor market variables and the federal and state level incarceration rates in the United States. We find a significant empirical association between the incarceration rate, 10th-percentile real-wage rate, and the unemployment rate, as well as the level of inequality. Specifically, the time-series analysis reveals a significant negative correlation between the incarceration rate and the 10th-percentile wage rate. Moreover, in all time-series regressions, the unemployment rate and the 40%-to-10% wage ratios are both positively correlated with the incarceration rate. In the state-level analysis, panel data regressions indicate that the unemployment rate, income inequality, and unemployment duration are positively associated with incarceration whereas the 10th-percentile wage is negatively correlated with the latter.

Does Demolition Lead to a Reduction in Nearby Crime Associated With Abandoned Properties?
Hye-Sung Han & Scott Helm
Housing Policy Debate, forthcoming


Scholars argue that housing abandonment increases area criminal activity. The link between abandoned properties and crime has led to the assumption that demolition of abandoned properties will stymie critical activity and thus improve neighborhood safety. Although cities spend millions of federal and local funds on demolitions every year, very little research has explored the empirical effects of demolitions on crime. Does demolition lead to a reduction in nearby crime? This study answers this question by quantifying the relationship between abandoned building demolition programs and nearby crime using a difference-in-difference approach on 559 abandoned buildings demolished in Kansas City, Missouri, between 2012 and 2016. This study finds that demolition of abandoned properties does not have any significant impact on nearby violent and property crime. This analysis shows that a change in nearby crime is attributable to differences in nearby socioeconomic and housing characteristics, rather than to the demolition of abandoned properties.


from the


A weekly newsletter with free essays from past issues of National Affairs and The Public Interest that shed light on the week's pressing issues.


to your National Affairs subscriber account.

Already a subscriber? Activate your account.


Unlimited access to intelligent essays on the nation’s affairs.

Subscribe to National Affairs.