Research
Publications
The Effect of Highly Publicized Police Killings on Policing: Evidence from Large U.S. Cities
forthcoming in the Journal of Public Economics (with Wei Long)
This paper examines whether highly publicized police killings of civilians have a widespread effect on policing activities. Focusing on such incidents in the United States during 2014-2016 and adopting different identification strategies, we study their effect in large U.S. cities. We conduct a single-city analysis of St. Louis and a multi-city analysis of 60 large cities. Our regression discontinuity and difference-in-differences estimates provide consistent and strong evidence that those high-profile killings reduced policing activities, including police self-initiated activities and arrests. The estimated reduction in self-initiated activities shows that police officers proactively withdrew from law enforcement activities, providing direct evidence of de-policing.
Improving Police Services: Evidence from the French Quarter Task Force
Journal of Public Economics, 2018, 164: 1-18. (with Wei Long)
This study sheds light on the improvement of police services by examining the French Quarter Task Force (FQTF) – an anti-crime program in New Orleans’ French Quarter. First, we provide new evidence that increasing police presence is effective in crime prevention. Our difference-in-differences estimates suggest that the FQTF, which increased police visibility in the French Quarter, reduced robberies, aggravated assaults, and thefts by 37.4 percent, 16.9 percent, and 13 percent, respectively. Second, our findings imply that the proper use of monitoring and incentive strategies has the potential to further improve police services. Exploiting the program’s change in management, we find that providing officers with more monitoring and performance incentives led the FQTF to reduce robberies by 22.12 and aggravated assaults by 5.56 each quarter.
The Effect of Legalizing Retail Marijuana on Housing Values: Evidence from Colorado
Economic Inquiry, 2018, 56(3): 1585-1601. (with Walt Mayer and Yanling Mayer)
Does legalizing retail marijuana generate more benefits than costs? This paper provides a first step toward addressing that question by measuring the benefits and costs that are capitalized into housing values. We exploit the time-series and cross-sectional variations in the adoption of Colorado’s municipality retail marijuana laws (RMLs) and examine the effect on housing values with a difference-in-differences strategy. Our estimates show that the legalization leads to an average 6 percent increase in housing values, indicating that the capitalized benefits outweigh the costs. In addition, we find suggestive evidence that this relatively large housing value appreciation is likely due to RMLs inducing strong housing demand while having no discernible effect on housing supply. Finally, we show that the effect of RMLs is heterogeneous across locations and property types.
Selected Media Coverage:
BBC(Business Matters, 48:03), Boston Globe, Financial Post, Mortgage Professional America, Pacific Standard, Realtor (Yahoo), SFGate, VegasINC
Greek Membership and Academic Performance: Evidence from Student-Level Data
Applied Economics, 2018, 50(29): 3185-3195.
Compared to other inputs of the “education production function”, less is known about the effect of social and non-classroom choices. This study examines whether joining fraternities and sororities improves academic performance. In order to account for the self-selection bias of Greek membership, I exploit plausibly exogenous cross-class variation in Greek student composition at the course-instructor level. My estimate shows that a 10 percentage point increase in Greek student composition translates to a 0.02 standard deviation increase in course grade for Greek students relative to non-Greek students. I further find that this effect is driven largely by low-achieving and middle-achieving white Greek members.
Does Simplifying Divorce and Marriage Registration Matter? Evidence from China
Applied Economics, 2016, 48(17): 1560-1572.
This paper evaluates the marital consequences of easier access to divorce and marriage by exploiting a major policy change in China that simplifies both. I first use a regression discontinuity design to examine the short-run effect and find that simplified registration immediately triggered more and faster divorces and marriages. In estimating the long-run effect, I adopt a difference-in-differences strategy that further exploits cross-sectional variation in urbanization rate. Results indicate that the positive effect on marital outcomes, especially on marriage rate, persisted in the medium run for four years.
Do Cell Phone Bans Change Driver Behavior?
Economic Inquiry, 2015, 53(3): 1420-1436.
In response to concerns that distracted driving due to cell phone use has become a threat to roadway safety, many states have passed laws that prohibit drivers from texting and talking on handheld cell phones. In light of recent evidence that these bans do not reduce traffic accidents, this paper asks whether this is because the laws are ineffective in reducing usage. Using data on observed driver cell phone usage combined with a difference-in-differences approach that exploits the within-state variation in the adoption of bans, I find that prohibiting drivers from texting and talking on handheld cell phones reduces each by 60 and 50 percent, respectively. This suggests the policy is effective at reducing the targeted behavior, which leads me to discuss other factors and behavioral responses that may counteract the reduction in observed usage.
Selected Media Coverage:
New York Times (Economix Blog)
Journal of Human Resources, 2013, 48(3): 821-854. (with Mark Hoekstra)
(working paper version) (previous version: NBER Working Paper No. 18134)
(Stata files) (basic homicide data in Excel format) (layperson-friendly description of methodology)
From 2000 to 2010, more than 20 states passed castle doctrine and stand-your-ground laws. These laws expand the legal justification for the use of lethal force in self-defense, thereby lowering the expected cost of using lethal force and increasing the expected cost of committing violent crime. This paper exploits the within-state variation in self-defense law to examine their effect on homicides and violent crime. Results indicate the laws do not deter burglary, robbery, or aggravated assault. In contrast, they lead to a statistically significant 8 percent net increase in the number of reported murders and non-negligent manslaughters.
Selected Media Coverage:
Wall Street Journal (Law Blog, Ideas Market Blog), New York Times, TIME, BBC, NPR, Chicago Tribune, Houston Chronicle, Dallas Morning News, Business Insider, Salon, Times Union, The Blaze, PoliticusUSA