Aaron Chalfin

Immigration Enforcement, Policing, and Crime

Research Summary In 2008, the federal government introduced “Secure Communities,” a program that requires local law enforcement agencies to share arrestee information with federal immigration officials. We employed the staggered activation of Secure Communities to examine whether this program has an effect on crime or the behavior of local police. Supporters of the program argue that it enhances public safety by facilitating the removal of criminal aliens. Critics worry that it will encourage discriminatory policing. We found little evidence for the most ambitious promises of the program or for its critics’ greatest fears. Policy Implications Although a large body of evidence reports that municipal police can have an appreciable effect on crime, involving local police in federal immigration enforcement does not seem to offer measurable public safety benefits. Noncitizens removed through Secure Communities either would have been incapacitated even in the absence of the program or do not pose an identifiable risk to community safety.

Are U.S. Cities Underpoliced? Theory and Evidence

We document the extent of measurement errors in the basic data set on police used in the literature on the effect of police on crime. Analyzing medium to large U.S. cities over 1960 to 2010, we obtain measurement error-corrected estimates of the police elasticity. The magnitudes of our estimates are similar to those obtained in the quasi-experimental literature, but our approach yields much greater parameter certainty for the most costly crimes, the key parameters for welfare analysis. Our analysis suggests that U.S. cities are substantially underpoliced.

Estimating the Crime Effects of Raising the Age of Majority

Research Summary The results of recent empirical research have shown that juveniles do not achieve complete psychosocial maturity until postadolescence and that processing juveniles as adults in the criminal justice system can be associated with elevated rates of criminal recidivism. In response to these as well as other concerns, several states have recently raised their legal ages of majority in the hopes of reducing juvenile offending rates. Connecticut enacted one such law change when it raised its age of majority from 16 to 17 in 2010 and then from 17 to 18 in 2012 for all but the most serious offenses. The effect of Connecticuts policy change on juvenile crime is examined in this study. To discern between changes in juvenile offending and changes in the propensity of police to arrest youthful offenders in the aftermath of a law change, we use two methodological approaches. Synthetic control methods are used to generate triple-differences estimates of the effect of Connecticuts policy change on juvenile arrests and overall crime rates by using a weighted average of other U.S. states as a natural comparison group. Next, by analyzing National Incident-Based Reporting System (NIBRS) data for a subset of Connecticuts local jurisdictions, we examine changes in age-specific juvenile arrests and changes in age-specific juvenile offending. The resulting evidence suggests that no discernable change in juvenile offending occurred. In addition, evidence exists that in some Connecticut jurisdictions, officer, rather than juvenile, behavior was impacted by this law change. Policy Implications Although raise-the-age policies may remain desirable for other policy reasons, no robust evidence of their effects on crime is yet available. Given the absence of such evidence of crime effects, policy makers interested in raise-the-age policies for their crime-reduction benefits might consider focusing on other juvenile justice policy initiatives with demonstrated crime-reduction benefits. Nevertheless, policy makers interested in these policies for other policy reasons can rest assured that there is no evidence that these policies exacerbate juvenile crime. The results of this study also suggest that the effects of “raise-the-age” policies on crime will be difficult to separate from recent declining trends in juvenile crime and arrests as well as from changes in police arrest decision making.