Steve Mello
Assistant Professor of Economics
Dartmouth College
I am an assistant professor of economics at Dartmouth College. My research interests are in public and labor economics, with a focus on inequality and the criminal justice system. You can view my CV here and can contact me at steve.mello@dartmouth.edu.
Research
Working Papers
Abstract
We study racial disparities in police use of force. A pervasive issue in studies of policing is that the available data are selected by the police. As a result, disparities computed in the observed sample may be biased if selection into the data differs by race. We develop a framework and econometric strategy for correcting this bias, using variation across officers in enforcement intensity to identify the racial composition of the unobserved population at risk of selection. Using detailed administrative data on arrests and force incidents from Chicago and Seattle, we find that Black civilians comprise 56 percent of arrestees but about 49 percent of potential arrestees. Correcting for sample selection doubles our measure of the racial disparity in force rates. Decompositions of the corrected force disparity reveal that about 70 percent is unexplained by other demographic and incident characteristics, suggesting an important role for officer discrimination. Our selection bias estimates meaningfully impact the conclusions drawn in the existing literature.
Cite
@techreport{gmw_selection,
title = {Selection Bias and Racial Disparities in Police Use of Force},
author = {Gon{\c c}alves, Felipe and Mello, Steven and Weisburst, Emily},
institution = {National Bureau of Economic Research},
type = {Working Paper},
series = {NBER Working Paper Series},
number = {34175},
year = {2025},
month = aug,
doi = {10.3386/w34175},
url = {https://www.nber.org/papers/w34175}
}
Abstract
We study the effects of cultural diversity training on employee behavior in the context of policing. Leveraging variation in the timing of a mandated diversity training, we find that Texas highway patrol officers respond to training by adjusting their racial composition of stops. The probability that a stopped motorist is white increases by 1.3 percentage points over the two years after training, and officers achieve this by stopping additional white motorists rather than reducing their stops of minorities. We find evidence that officers stop less “guilty” white motorists after training, suggesting that the training reduces troopers’ lenience towards white drivers.
Abstract
We use geocoded data on gun violence incidents to document disparities in exposure to neighborhood violence by race and income. We then explore the historical roots of these disparities, using a border discontinuity design approach to estimate the causal effect of “redlining” policies during the Great Depression on contemporary gun violence. The prevalence of gun violence changes sharply at borders associated with changes in creditworthiness designations in the 1930’s. A decomposition exercise suggests that five percent of contemporary group disparities in exposure to neighborhood violence can be explained by the persistent effects of historical “redlining.”
Abstract
We provide estimates to inform the potential tradeoff between the crime reduction benefits and social costs associated with investments in policing. Using stated-choice experiments in an original survey, we estimate willingness to pay for reductions in violent crime and police use of force. Our survey results indicate that citizens are willing to accept four additional violent crimes in return for one fewer force incident. Accounting for these costs has important implications for studies of police cost-effectiveness. Original estimates of the causal effects of marginal officers on crime and use of force, using day-to-day variation in predetermined staffing levels, show an empirically important role for force in cost-benefit calculations.
Abstract
Unexpected expenses are common and can have significant economic consequences, particularly for individuals with limited financial buffers. This paper examines the long-term effects of modest financial shocks stemming from minor car crashes. Leveraging a unique dataset combining car crash reports with Census and tax records, we estimate the causal impacts of these shocks on employment, earnings, and related indicators of economic and social well-being. We find that such shocks lead to persistent setbacks in employment and earnings, particularly among financially vulnerable populations. These effects are substantially mitigated during periods of higher liquidity and among individuals with access to greater social supports.
Publications
Abstract
We study the implications of police discretion for public safety. Highway patrol officers exercise discretion over fines by deviating from statutory fine rules. Relying on variation across officers in this discretionary behavior, we find that harsher sanctions reduce future traffic offending and crash involvement. We then show that officer discretion over sanctions decreases public safety by comparing observed reoffending rates with those in a counterfactual without discretion, estimated using a novel approach leveraging officers who practice no discretion. About half the safety cost of discretion is due to officer decisions which result in harsh sanctions for motorists who are least deterred by them. We provide evidence that this officer behavior is attributable to a preference for allocating harsh fines to motorists with higher recidivism risk, who are also the least responsive to harsher sanctions.
Cite
@techreport{gm_discretion,
title = {Police Discretion and Public Safety},
author = {Gon{\c c}alves, Felipe and Mello, Steven},
institution = {National Bureau of Economic Research},
type = {Working Paper},
series = {NBER Working Paper Series},
number = {31678},
year = {2023},
month = sep,
doi = {10.3386/w31678},
url = {https://www.nber.org/papers/w31678}
}
Abstract
While survey evidence suggests widespread financial fragility in the U.S., causal evidence on the implications of typical, negative income shocks is scarce. I estimate the impact of speeding fines on household finances using administrative traffic citation records and a panel of credit reports. Event studies reveal that fines averaging $195 are associated with a $34 increase in unpaid bills in collections. Given additional evidence that fine payment explains this effect and that default is the “last resort” for households, I interpret this finding as suggesting rates of inability to meet unplanned expenses which are consistent with the survey evidence. I also find that fines are associated with longer-run declines in credit scores, borrowing limits, and the likelihood of appearing as employed in payroll records covering a subset of large, high-paying employers. This impact on employment situations appears attributable to the diminished financial position of households rather than, e.g. downstream license suspensions.
Cite
@article{mello_fines,
title = {Fines and Financial Wellbeing},
author = {Mello, Steven},
journal = {Review of Economic Studies},
volume = {92},
number = {5},
pages = {3340--3374},
year = {2025},
month = sep,
doi = {10.1093/restud/rdae111}
}
Abstract
We estimate the degree to which individual police officers practice racial discrimination. Using a bunching estimation design and data from the Florida Highway Patrol, we show that minorities are less likely to receive a discount on their speeding tickets than White drivers. Disaggregating this difference to the individual police officer, we estimate that 42 percent of officers practice discrimination. We then apply our officer-level discrimination measures to various policy-relevant questions in the literature. In particular, reassigning officers across locations based on their lenience can effectively reduce the aggregate disparity in treatment.
Cite
@article{gm_apples,
title = {A Few Bad Apples? Racial Bias in Policing},
author = {Gon{\c c}alves, Felipe and Mello, Steven},
journal = {American Economic Review},
volume = {111},
number = {5},
pages = {1406--1441},
year = {2021},
month = may,
doi = {10.1257/aer.20181607}
}
Abstract
I exploit a natural experiment to estimate the causal effect of police on crime. The American Recovery and Reinvestment Act increased funding for the Community Oriented Policing Services (COPS) hiring grant program from less than $20 million over 2005–2008 to $1 billion in 2009. Hiring grants distributed in 2009 were allocated according to an application score cutoff rule, and I leverage quasi-random variation in grant receipt by comparing the change over time in police and crimes for cities above and below the threshold in a difference-in-differences framework. Relative to low-scoring cities, those above the cutoff experience increases in police of about 3.2% and declines in victimization cost-weighted crime of about 3.5% following the distribution of hiring grants. The effects are driven by large and statistically significant effects of police on robbery, larceny, and auto theft, with suggestive evidence that police reduce murders as well. Crime reductions associated with additional police were more pronounced in areas most affected by the Great Recession. The results highlight that fiscal support to local governments for crime prevention may offer large returns, especially during bad macroeconomic times.
Cite
@article{mello_cops,
title = {More COPS, Less Crime},
author = {Mello, Steven},
journal = {Journal of Public Economics},
volume = {172},
pages = {174--200},
year = {2019},
month = apr,
doi = {10.1016/j.jpubeco.2018.12.003}
}