Research
Working Papers
Revisiting the Unintended Consequences of Ban the Box
with David Wasser
Abstract: Ban-the-Box (BTB) policies intend to help formerly incarcerated individuals find employment by delaying when employers can ask about criminal records. We revisit findings in Doleac and Hansen (2020) showing BTB causes discrimination against minority men. Their results using the Current Population Survey (CPS) are based on very small cells prone to sampling error or spurious treatment effects. We correct miscoded BTB laws and show that estimates using the American Community Survey (ACS) do not have this problem. Using the ACS, we find no evidence of discrimination: employment effects are near zero, precisely estimated, and not economically meaningful.
Negative Externalities of Temporary Reductions in Cognition: Evidence from Particulate Matter Pollution and Fatal Car Crashes
with Travis Roach
Abstract: Mounting causal evidence shows particulate matter pollution reduces real-time cognitive function and increases aggressive behavior by reducing neural connectivity through oxidative stress and neuro-inflammation. We investigate a setting in which reduced cognition can generate significant private and external costs: driving. Using exogenous variation in wind direction, we show that higher PM2.5 exposure results in more fatal car crashes and fatalities. Further, only same-day pollution exposure increases accidents and fatalities, highlighting the immediate negative effects of high-pollution days. An across-the-board one standard deviation reduction in fine particulate matter pollution would have averted over 2,800 motor vehicle fatalities in 2019.
Supply-Side Opioid Restrictions and the Retail Pharmacy Market
with Brandyn F. Churchill
Abstract: Policymakers routinely limit the sale of goods thought to be of risk to public health. Despite a large literature studying how these supply-side interventions affect consumer outcomes, relatively less is known about whether and how these policies affect firm performance. Using 2000-2018 National Establishment Time-Series data and a difference-in-differences strategy, we show that state “pill mill” laws intended to reduce the overprescribing of opioids reduced retail pharmacy sales and employment. These reductions were driven by an increase in the number of pharmacy closures, particularly among standalone establishments, while surviving establishments experienced modest improvements in market outcomes.
Do Uber and Lyft Reduce Drunk-Driving Fatalities?
Abstract: This paper investigates whether Uber and Lyft lead to reductions in drunk driving, as measured by city-level drunk-driver-related motor vehicle fatalities and fatal crashes. I use a difference-in-differences method that exploits the variation in the timing of Uber and Lyft entry for the 100 most populous U.S. cities and a Poisson model to account for the fact that crashes and fatalities are count data. Using monthly city-level Fatality Analysis Reporting System (FARS) data for 2006 to 2016, I find small declines in drunk-driver-related fatal motor vehicle incidents and small increases in overall fatal motor vehicle incidents, but I cannot reject the null hypothesis of no effect of Uber or Lyft on these outcomes. Event studies suggest that drunk-driver-related and overall fatal motor vehicle incidents decline several years after the entry of Uber or Lyft into a city.
Publications
The Impact of Smoking Bans in Bars on Alcohol Consumption and Smoking
Journal of Law and Economics, 68(1): 183-214. 2025. https://www.journals.uchicago.edu/doi/10.1086/731698
Abstract: Governments implemented smoking bans in bars to target smoking-related externalities, but these bans may also affect drinking. This paper studies smoking bans’ effects on alcohol consumption and smoking behavior. I estimate a difference-in-differences model that exploits spatial and temporal variation in smoking bans. Bans result in a 1-drink-per-month (5 percent) increase in intensive-margin alcohol consumption and no economically meaningful effects on smoking. Effects on alcohol consumption are concentrated among current and former smokers. These results imply that smoking bans lead to unintended consequences in the form of increased alcohol consumption.