Current Projects


911 Call Analytics

Calls to 911 in large urban jurisdictions are typically first assigned to a responding service (e.g., police, medical, fire), and are then assigned priority codes determining the speed and nature of the service's response. These human-assigned call and priority codes may not be optimal. For example, calls involving mental health issues may be assigned to policing agencies when they might more appropriately be assigned to medical professionals. Calls assigned to policing agencies may be assigned priority codes that are influenced by call taker biases. Working with a large urban policing agency, we are exploiting the as-if random assignment of 911 calls to call takers to evaluate both the process by which call and priority codes are assigned to calls, and the causal effects of call and priority codes on outcomes.

911 Response Field Experiment

Many policing agencies seek to improve their relationships with the communities they police, yet struggle to find effective means to do so. Working with a large urban policing agency, we are developing a randomized controlled trial of a platform that pushes an SMS-based survey to recent 911 callers, asking them to provide feedback on how they were treated by responding officers. Responding patrol officers may then access their average survey ratings, as well as those of the other officers in their unit, through a web-based interface. The platform may both incentivize responding officers to treat 911 callers with greater professionalism, and increase caller satisfaction with the police response to their call. More generally, the platform may provide an effective means for agencies to receive real time feedback from the communities they police.

Prosecutorial Reform Initiative

Prosecutors play a vital role in the criminal justice system. After an arrest, prosecutors have numerous choices to make regarding whether and how to pursue prosecution of an offense. In many jurisdictions, prosecutors use this discretion to pursue prosecutions of subfelony violations to the full extent of the criminal law. In these jurisdictions, cases involving subfelony offenses typically consume a large share of law enforcement, prosecutorial, and judicial resources. Yet it is unclear whether this practice reduces offender recidivism; the practice may actually result in increased recidivism, and/or the escalation of minor offending into more serious offending. Working with a large urban district attorney's office, and exploiting the as-if random assignment of assistant district attorneys to subfelony cases, we are investigating the impact on offender recidivism of the use of prosecutorial discretion to reduce the incidence of prosecution for subfelony offenses.

Jail Data Initiative

The problem of overincarceration has received considerable attention of late. The focus of this attention, however, has largely been on state and federal prison systems. Often overlooked are local jails. In any given year, approximately 11 million Americans will be detained in a local jail, often because they lack the funds to post bail. Yet we know little about the consequences of this widespread practice of pretrial detention. It is possible that longer periods of pretrial detention actually increase offender recidivism, and/or escalate petty offending into more serious offending. Our data science team is crawling the daily jail rosters of over 1,000 county jails, recording defendant-level data on pretrial detention and offender recidivism, as well as jail-level data on daily jail capacity, and merging these data with crawled defendant-level criminal case and incarceration records. Using these data we will then estimate the impact of the length of pretrial detention on offender recidivism, leveraging daily variation in local jail capacity.

Identifying Sex Trafficking

Sex trafficking is a crime of extraordinary violence visited largely upon vulnerable girls and young women. Its frequency is likely severely underreported, given the isolation within which its victims are kept. Working with a multi-university team, we are extracting structured content from a very large corpus of online commercial sex ads and provider reviews crawled over a period of several years. We are then looking for features in this extracted content that are suggestive of the presence of sex trafficking, and that may assist law enforcement agencies in identifying newly posted ads and reviews associated with trafficking. Initial results suggest that urban public school district calendars may be a good indicator of the presence of sex trafficking, highlighting for agencies the importance of investigating online sex ads posted on days when high school-aged girls are not in school, but adults are at work.

Policing for Revenue

There is widespread concern about the deployment of law enforcement resources to generate revenue for fiscally stressed jurisdictions. Yet rigorous evidence of the practice has been elusive. Working with a large regional highway patrol agency, we are exploiting a discontinuity in the allocation of revenue received from traffic citations to explore the consequences of fiscal incentives for both law enforcement and driver behavior. We find that traffic safety enforcement increases in the towns wherein the regional government receives more citation revenue. We further find that these fiscal incentives increase roadway safety in the high-revenue jurisdictions, but decrease roadway safety in the low-revenue jurisdictions. Finally, we find that these fiscal incentives have negative economic consequences for cited drivers in the high-revenue jurisdictions.


Criminal Defendant Equity Project

Ensuring that criminal defendants are treated equally before the law is one of the most important imperatives of criminal justice institutions. Yet judges’ retention incentives may lead to the unequal treatment of defendants, even in appellate cases. Working with extensive data crawled from public access websites, including the texts of every criminal opinion issued by New York State's intermediate appellate courts between 2003 and 2017,  and demographic and criminal history data on all criminal defendants processed by New York State's Department of Corrections since the 1970s, we are estimating the impact of judicial retention incentives (both reelection and reappointment) on the treatment of criminal defendants in intermediate appellate court cases.

Firearm Trafficking Analytics

Several websites host online firearms markets. Many sellers on these sites are not federally licensed firearms dealers. Federal law and most state laws do not require these private firearms sellers to conduct background checks on potential buyers. Even when state statutes do require background checks for purchases from private online dealers, as in New York State, these sales are difficult to monitor and track. As a result, it is relatively easy in these states for those prohibited from purchasing firearms to do so via online firearms markets. Working with the Regional Gun Violence Research Consortium, we are developing a project to identify and measure the incidence of online firearms trafficking, and to evaluate the efficacy of state and local regulations to reduce this incidence.

Civil Asset Forfeiture Project

Civil asset forfeiture allows law enforcement agencies to seize property upon the suspicion of criminal activity. While the practice may deter some criminal activity, it may also divert agency resources away from other productive pursuits, and may impose economic costs unevenly. We are collecting data on the amounts and types of assets being seized and forfeited by state and local law enforcement agencies, whether forfeitures are contested, demographic data on the subjects of asset forfeiture, and cross-state and within-state variation in civil asset forfeiture statutes. Using these data we are building predictive models of the incidence and effects of civil asset forfeiture.

Community Policing

Although "community policing" has become a popular catchphrase, little is known systematically about whether community policing can improve communities' trust in their local law enforcement agencies. Working with a large urban police force in South America, we are analyzing whether randomly assigned town hall meetings bringing together residents and officers to discuss policing strategies can improve trust in law enforcement. 

Social Networks and Violent Crime

Recent work has suggested that violent criminal behavior is often perpetrated through closely knit social networks, networks that facilitate overlapping forms of crime often associated with high rates of gun violence (e.g. drugs, guns, sex trafficking). This work suggests that identifying social networks with the potential to either encourage or discourage violent criminal behavior may be a promising policing strategy. Working with two large urban police forces in South America, we are analyzing whether randomized police interventions delivered through socially central individuals can reduce participation in violent criminal activity.

Domestic Violence Policing

Law enforcement agencies in developing countries often fail to appropriately respond to domestic violence complaints. Working with a state policing agency in India, we are conducting a randomized controlled trial of several interventions designed to increase the efficacy of the police response to domestic violence complaints, including randomized officer training in alternative dispute resolution and random assignment of paralegals to assist in case development.