Work Under Review

“On the Tension Between Due Process Protection and Public Safety: The Case of an Extensive Procedural Reform” (Forthcoming Journal of Law and Economics 2027) (with Camilo Acosta and Daniel Mejia) See Methodological Appendix

We study how large procedural reforms reshape deterrence by tracing equilibrium adjustments across multiple margins of the criminal justice system. Using the staggered rollout of Colombia’s comprehensive adversarial criminal procedure reform in a civil-law setting (2005-2008), we estimate both intended administrative effects and unintended effects on enforcement and crime. The reform aimed to strengthen due process protections, reduce reliance on pretrial detention, accelerate case processing, and expand early termination mechanisms. We find that the reform achieved most of its explicit objectives: pretrial detention declined by 13-28%, procedural duration fell by 19%, settlements increased by 41-65%, and adjudication rose substantially. At the same time, the reform reduced enforcement activity and case progression: arrest rates fell by 39%, and clearance rates—the share of reported crimes in which prosecutors file charges before a judge—by 16-27%. Consistent with a reduction in the certainty component of deterrence, crime increased after implementation; property crime by 29% and violent crime by 15%. These findings highlight a key implication of adversarial procedural redesign: reforms that improve internal efficiency can alter enforcement and charging behavior in ways that affect public safety. More broadly, they underscore the importance of evaluating procedural reforms as bundled institutional changes and measuring their effects along the full case-processing pipeline, from complaint to case resolution, rather than inferring mechanisms from crime outcomes alone. 

“The Failed War on Pre-Trial Detention: Evidence from a Quasi-Experimental Reform” (R&R Journal of Legal Studies)

During the 1990s and 2000s, 70 percent of Latin American countries transitioned from an inquisitorial criminal procedure to a U.S. adversarial model in a phenomenon known as the Latin American Criminal Procedure Revolution (LACPR). The LACPR involved more than 19 countries and cost around 1.51 billion dollars. Almost two decades after its implementation, the impact of the most significant procedural reform undertaken on the continent remains largely unexplored. Using Colombia as a study case, I explore the LACPR effect in pre-trial detentions using two methodological strategies. First, I exploit the exogenous variation resulting from the LACPR gradual implementation to estimate a difference-in-difference and an event study model. Secondly, I assess the impact of the LACPR in pre-trial admission and release rates using a regression analysis controlling for cofounding variables and time trends. The results provide compelling evidence that the U.S. adversarial model decreased the number of inmates in pre-trial detention, specifically male detainees. However, the results show that the decline is not associated with a decrease in the use of pre-trial detention (human rights gain) but with an increase in procedural speediness (efficiency gain). 

“Evidence of Donor Bias in Chicago Police Stops” (R&R Science)

This study provides empirical evidence that private donations to police departments can influence the spatial allocation of discretionary enforcement. Using a quasi-experimental design in Chicago, we find that after 7-Eleven sponsored a police foundation gala, investigatory stops, particularly pedestrian stops, increased near its stores, with no robust corresponding change in vehicular stops and no detectable change in crime. The increase fell disproportionately on Black pedestrians, either through race-neutral enforcement applied to a racially skewed pedestrian population or through race-differentiated policing decisions. These findings suggest that even modest private donations can distort the allocation of public law enforcement resources toward donor-affiliated locations.

“The Diffusion of Policing Alternatives in U.S. Cities After the George Floyd Protests” (R&R American Sociological Review)

Why do some city governments adopt social movement policy demands while others do not? The murder of George Floyd ignited one of the largest social movement uprisings in U.S. history, sparking a national debate about police reform and providing a critical test case for understanding the conditions that drive policy diffusion in cities. We provide the first systematic analysis of policing alternative adoption in U.S. cities from 2017 to 2023, examining crisis response alternatives and violence prevention offices. Drawing on a dataset of 320 cities with populations over 100,000, we find that city governments embedded in policy learning communities adopted these programs at higher rates than non-member city governments, 36.7% vs. 5.4% for crisis response alternatives and 35.2% vs. 3.3% for violence prevention offices. We find that neither protest pressure nor network embeddedness alone explains adoption; it is their combination that explains which city governments acted. When the 2020 Black Lives Matter protests created the political conditions for change, city governments with pre-existing ties to policy learning communities were positioned to translate protest pressures into concrete reforms, adopting crisis response alternatives at 6.8 times the rate and violence prevention offices at 10.7 times the rate of non-member city governments. More broadly, these findings illuminate a general mechanism of institutional change: social movement demands are most likely to produce an institutional response when external shocks that open policy windows coincide with pre-existing organizational infrastructure that has already built policy templates, political relationships, and expert knowledge needed to act.

Peer-Reviewed Publications

“Cumulative Risks of Multiple Outcomes in New York City” Demography (with Peter Hepburn and Issa Kohler-Hausmann)

“How Political Dynasties Concentrate Advantages within Cities: Evidence from Crime and City Services in Chicago”, 2024, Social Forces (with Stephanie Ternullo and Robert Vargas)

Book Chapters

Zorro Medina, A., (Under contract) “Latin American Expansion: A Quasi-Experimental Evaluation of a Criminal Procedural Reform.” In Iturralde, M., and Sozzo, M. Routledge Handbook on Crime and Punishment in Latin America

Zorro Medina, A., Forthcoming “An Experimental Evaluation of Criminal Settlements in Colombia” (“Una evaluación experimental de los acuerdos penales en Colombia”). In Langer, M. and Sozzo, M.

Zorro Medina, A., Forthcoming “John Pfaff and the Theories of Prison Growth” (“John Pfaff y las teorías sobre el crecimiento de la población reclusa”). In Ariza, L. and Tamayo, F. (coord) “Contemporary Thinking and Research on Crime and Punishment” (“Pensamiento e investigación contemporánea sobre el crimen y el castigo”). Bogotá, Colombia: Uniandes

Zorro Medina, A., 2021. “The Cost of Imprisonment” (“Los costos del encarcelamiento”). In Ariza, L. and Iturralde, M. (coord.) “The Prison in Colombia: Challenges and Perspectives” (“La prisión en Colombia: desafíos y perspectivas”). Bogotá, Colombia: Uniandes

Zorro Medina, A., Acosta, C. and Hernández, N., 2016. “An Economic Approach of the Pre-Trial Detention” (“Un enfoque económico a la detención preventiva”). In Lozano, E. (coord), “Theory and Empirical Economic Analysis of the Colombian Law” (“Teoría y puesta en práctica del análisis económico del derecho en Colombia”). Bogotá, Colombia: Uniandes

Work in Progress

Zorro Medina, A. “The Effect of the Chicago Anti-Gang Ordinance on Crime” (Results available/draft in preparation)

In 1992 Chicago enacted an anti-gang loitering ordinance under which the police issued more than 89,000 dispersal orders and made more than 42,000 arrests in three years. Yet the effects of the original 1992 ordinance on crime rates remain highly unexplored. In this paper, I propose to use a synthetic control method to evaluate the effects of this ordinance on urban crime in Chicago. The results suggest that in the absence of the ordinance, crime rates would have been lower. 

Braccacini, F., De la Rosa, C. and Zorro Medina, A. “Legitimacy Perception of Criminal Justice Systems: Evidence from an Experimental Setting” (Results available/draft in preparation)

This article explores the consequences of electing prosecutors via popular vote in the U.S. from two perspectives: the legitimacy of the criminal justice system and punitivity outcomes. Our results suggest that although previous literature has pointed out that during election years prosecutors tend to be more punitive, on average elected prosecutors tend to be less punitive during the rest of the term.  

Hepburn, P., Kohler-Hausmann, I. and Zorro Medina, A. “Estimating the Risk and Scope of Misdemeanors” (Results available/draft in preparation)

This article asks if measures and methods used in research linking the operation of the criminal justice system to the reproduction of inequality—focused on conviction and custodial sentences in the felony context—are appropriate to the subfelony world. While research on the felony justice system has largely focused on case outcomes (i.e., felony conviction and imprisonment), we argue that analysis of the subfelony world should be attuned to elements of the process, such as arrest frequency and scope. Using various methods, we document declines in misdemeanor conviction risk, increases in the individual-level intensity of misdemeanor arrest over time, and racial/ethnic variations in both. 

 “Neoliberalism vs. Bureaucracy: Evidence from Mass-Incarceration in Colombia”

This paper provides the first causal evaluation of these theories on the expansion of the Latin American carceral state. Using Colombia as a case study, I show that adopting the criminal procedural adversarial model caused an increase in the prison population of 30%, remarkably increasing the male convicted population in prison by 32%. I identify the introduction of plea bargaining as the primary driver of prison population growth. However, while plea bargaining increased the male prison population, it decreased the female incarceration rate by 25%. 

Public Scholarship

“Baseline of Human Rights in Prisons in Colombia“, 2017 (with Libardo Ariza, Manuel Iturralde, Nicolás Torres, Julián Urrutía)

“Releases from Prison during Covid”, 2020, El Espectador

“Chicago Police Recover Less than 20% of Carjacked Vehicles”, 2022 (with Robert Vargas, Caitlin Loftus, and Kiran Misra)

“Unintended Consequences of Legal Reforms”, 2021 (podcast episode Parsing Sciences available on Spotify, Apple Music and listen notes)