When the law changes: The impact of a change in criminal justice policy on a long-term hot spot policing program (original) (raw)
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Broken windows policing and crime: Evidence from 80 Colombian cities
2021
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 build grids of 200 × 200 meters over the urban perimeter of all cities and produce event studies to look at the effects of shocks in police activity in the periods to follow. We use spikes in the number of arrests with no warrant—which are more likely associated with unplanned police presence—as a proxy for shocks in broken windows policing. As expected, we observe an increase in crimes during the shock period, as each arrest implies at least one crime report. In the following periods, crimes decrease both in the place of the arrests and the surroundings. With many treated grids and many places exposed to spillovers, these effects add up. On aggregate, the crime reduction offsets the observed increase during the shock period. Direct effects are more immediate and precise at low crime grids, but beneficial spillovers seem more relevant at crime hot spots. The effects of broken windows policing circumscribe to cities with low or moderate organized crime, consistent with criminal organizations planning their activities more systematically than disorganized criminals.
Hot Spots Policing in a High Crime Environment: An Experimental Evaluation in Medellín
SSRN Electronic Journal, 2019
Objectives: 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 sample in a dense network of streets, we use randomization inference for hypothesis testing. We also use non-experimental streets to test for spillovers onto non-hot spots, and examine aggregate effects citywide. Results: Our results show an improvement in short term security perceptions and a reduction in car thefts, but no direct effects on other crimes or satisfaction with policing services. We see larger effects in the least secure places, especially for short term security perceptions, car thefts and assaults. We find no evidence of crime displacement but rather a decrease in car thefts in nearby hot spots and a decrease in assaults in nearby non-hot spots. We estimate that car thefts decreased citywide by about 11 percent. Conclusions: Our study highlights the importance of context when implementing hot spots policing. What seems to work in the U.S. or even in Bogotá is not as responsive in Medellín (and vice versa). Further research-especially outside the U.S.-is needed to understand the role of local crime patterns and police capacity on the effectiveness of hot spots policing. JEL codes: K42, O17, E26, J48, C93.
Rationale, 2019
Brazil has been one of the most prominent country case studies in academic research charting the relationship between crime and economic development. The issue of violent crime, in particular, has taken centre stage in the past year, as record high murder rates have coincided with the election of President Jair Bolsonaro. His campaign promised of tough anti-crime policies, which resonated with Brazil's track record of a mano dura-heavy-handed-approach to public security. The city of Rio de Janeiro, specifically, has undertaken a process of militarisation and implementation of police operations in its favelas to combat violence and improve security before the 2014 FIFA World Cup and the 2016 Olympic Games. Using an instrumental variable regression , we control for endogeneity in crime rates across the Integrated Circumscriptions of Public Security (CISP) in the municipality of Rio de Janeiro. This is done by utilising the implementation of the 38 Unidades de Policia Pacificadora (Police Pacification Units, UPPs) to study the effects of crime on nightlight data, a proxy for income at the local level. Our regression results suggest that, when controlling for homicide rates and income levels in neighbouring CISPs in the prior month, UPPs had a statistically significant effect on reducing crime rates. Contrary to the academic literature, however, our primary findings indicate that decreases in crime rates actually corresponded with statistically significant decreases in future nightlights. We explore possible reasonings for this, potential for future studies, and the effects of other types of violent crime, such as rape and theft, robberies, and deaths by police officers on future income levels.
International Review of Law & Economics, 2019
The objective of this study was to assess the effect of the new Code of Criminal Procedure (NCCP) on crime and perceived risk of crime in Peru. The progressive implementation of the NCCP allowed us to (1) use differences-indifferences (to control for the effect of time invariant characteristics) with matching estimator (to control for bias selection), and (2) to differentiate the impact based on whether the NCCP was earlier (2010) or later (2012) implemented. A large sample was used (N = 445,838). The impact of NCCP was evaluated on aggregated and individual measures of crime and perceived risk of crime, including violent crime. Results show that the impact of the NCCP on crime was low and lost strength every year. Moreover, the impact is selective (it only affects some forms of crime) and differentiated (it reduces some forms of crime while increasing others). It also reduces the most common forms of crime committed with arms. On the other hand, the NCCP decreased most indicators of perceived risk of crime. Our findings point to the need to better manage the implementation of the NCCP as well as to highlight the deterioration of its impact mechanisms in time (particularly its celerity).
Evidence that curtailing proactive policing can reduce major crime
Nature Human Behaviour, 2017
Governments employ police to prevent criminal acts. But it remains in dispute whether high rates of police stops, criminal summonses and aggressive low-level arrests reduce serious crime 1-7. Police officers target their efforts at areas where crime is anticipated and/or where they expect enforcement will be most effective. Simultaneously, citizens decide to comply with the law or commit crime partly on the basis of police deployment and enforcement strategies. In other words, policing and crime are endogenous to unobservable strategic interaction, which frustrates causal analysis. Here, we resolve these challenges and present evidence that proactive policing-which involves systematic and aggressive enforcement of low-level violations-is positively related to reports of major crime. We examine a political shock that caused the New York Police Department (NYPD) to effectively halt proactive policing in late 2014 and early 2015. Analysing several years of unique data obtained from the NYPD, we find that civilian complaints of major crimes (such as burglary, felony assault and grand larceny) decreased during and shortly after sharp reductions in proactive policing. The results challenge prevailing scholarship as well as conventional wisdom on authority and legal compliance, as they imply that aggressively enforcing minor legal statutes incites more severe criminal acts. In the last few decades, proactive policing has become a centrepiece of 'new policing' strategies across the globe 8,9. The logic, commonly associated with the broader theory of order maintenance policing (OMP; also known as broken windows), is that rather than wait for citizens to report criminal conduct, law enforcement should proactively patrol communities, maintaining order through systematic and aggressive low-level policing 1,10,11. According to proponents, increasing police stops, quality-of-life summonses, and low-level arrests deters more serious criminal activity by signalling that the area is being monitored and that deviance will not be tolerated 12,13. As a corollary, following a phenomenon termed the Ferguson effect, disengaging from proactive policing emboldens criminals, precipitating spikes in serious crime 14. But while elected officials commonly justify proactive policing by pointing to the enforcement of legal statutes, the strategy's efficacy continues to be debated 5,15,16. A serious concern is that proactive policing diverts finite resources and attention away from investigative units, including detectives working to track down serial offenders and break up criminal networks 8,17. Proactive policing also disrupts communal life, which can drain social control of group-level violence 18. Citizens are arrested, unauthorized markets are disrupted, and people lose their jobs, all of which create more localized stress on individuals already living on the edge 19,20. Such strains are imposed directly through proactive policing, and thus are independent from subsequent judgments of guilt or innocence 21. Inconsistency in aggressive low-level policing across community
The Unintended Consequences of the U.S. Adversarial Model in Latin American Crime
SSRN Electronic Journal, 2016
During the 1990s, Latin America experienced a criminal procedural revolution (LACPR) when approximately 70% of its countries abandoned their inquisitorial system and adopted the U.S. adversarial model. Following the LACPR, the region experienced a dramatic increase in crime, consolidating it as one of the most violent areas in the world. Despite previous empirical evidence indicating that procedural law affects criminal behavior, the effects of the LACPR continue highly unexplored. In this paper, we use the Latin American case to evaluate the impact of an adversarial reform on crime rates. Exploiting the quasi-experimental implementation of the reform in Colombia, we use an event study approach combined with differences-indifferences to estimate the reform's effects on criminal activity. Despite the opposite incentives the reform created, we find an increase associated with the procedural transformation in overall crime rates (22%), violent crime (15%), and property crime (8%). We also observe a dramatic decrease in drug offenses associated with lower arrest rates. Our findings contribute to the literature on Latin American crime and the link between procedural law and criminal behavior.
Police, Crime and the Problem of Weak Instruments: Revisiting the “More Police, Less Crime” Thesis
Journal of Quantitative Criminology, 2015
Objectives: A key question in the general deterrence literature has been the extent to which the police reduce crime. Definitive answers to this statement, however, are difficult to come by because while more police may reduce crime, higher crime rates may also increase police levels, by triggering the hiring of more police. One way to help overcome this problem is through the use of instrumental variables (IV). Levitt, for example, has employed instrumental variables regression procedures, using mayoral and gubernatorial election cycles and firefighter hiring as instruments for police strength, to address the potential endogeneity of police levels in structural equations of crime due to simultaneity bias. Methods: We assess the validity and reliability of the instruments used by Levitt for police hiring using recently-developed specification tests for instruments. We apply these tests to both Levitt's original panel dataset of 59 U.S. cities covering the period 1970 to 1992 and an extended version of the panel with data through 2008. Results: Results indicate that election cycles and firefighter hiring are "weak instruments"weak predictors of police growth that, if used as instruments in an IV estimation, are prone to result in an unreliable estimate of the impact of police levels on crime. Conclusions: Levitt's preferred instruments for police levels-mayoral and gubernatorial election cycles and firefighter hiring-are weak instruments by current econometric standards and thus cannot be used to address the potential endogeneity of police in crime equations.
Do Police Reduce Crime? A Reexamination of a Natural Experiment
2013
We reexamine a natural experiment first studied by Di Tella and Schargrodsky (2004, "DS"). In response to a 1994 terrorist attack against a Jewish Community Center in Buenos Aires, the government implemented 24-hour police surveillance on city blocks with Jewish institutions. Using a control group of blocks without Jewish institutions, DS applied difference-indifferences , finding that increased policing substantially reduced car theft. We explain how the reallocation of police resources from unprotected to protected blocks, shifts in criminal activity to avoid 24-hour police patrols, and a parking prohibition on protected blocks undermine the original design. The intervention may have displaced, rather than deterred, crime, invalidating the original control group. To investigate this possibility, we reanalyze the data with two modifications. First, we disaggregate the original control group into near and far blocks, with displacement much more likely to affect near blocks. Second, to reduce model sensitivity, we match exactly on all covariates, including neighborhood and the full pretreatment car theft time series. Consistent with displacement, we find that crime increases on near blocks relative to protected blocks, but that crime rates on protected and far blocks are indistinguishable.
Police and Crime: Further Evidence from a Quasi-Natural Experiment
SSRN Electronic Journal, 2018
The paper investigates the effect of police presence on homicides at the municipality level in Brazil during the January 2010 to December 2014 period. For this purpose, occasional and illegal police strikes are considered as relevant shocks in a quasi-natural experiment. After controlling for different variables that explain heterogeneity across municipalities, it is possible to identify a sizeable effect accruing from police strikes on the occurrence of homicides. Despite a conservative analysis that involves temporal and spatial aggregation of variables, the evidence indicates that police strikes lead, on average, to a 16% increase in the homicide rate if one considers a broader sample of 3597 municipalities. The focus of the analysis for a large and heterogeneous country also partially may mitigate concerns for external validity that had been raised in the context of previous studies in the related literature. JEL-Codes: C230.