Working Papers
Clark, Tom S., and John W. Patty. "Which Issues Should We Decide? Coalitions and Agenda Setting." (working paper)
It is well-known that the classic model of multidimensional policy choice generically has no core under majority rule. We show that this instability has a simple anatomy. Fixing the preferences of a group's members and a prevailing status quo, every proposal that a majority would adopt falls into exactly one of three categories, distinguished entirely by which of its narrowings the body would also adopt. Convenient vehicles are proposals every issue of which would be adopted on its own; bundling them is a convenience. Bridging vehicles are proposals that pass as a package but fail if any issue is removed—the spatial analogue of a logroll, sustained by a coalition of coalitions drawn from opposite sides of the policy space. Clown cars are the residual: proposals that pass and would continue to pass even if some of their issues were stripped away. We show that bridging vehicles are exactly the adopted proposals that move policy away from the dimension-by-dimension median on every issue (when there are two issues), that they exist generically whenever the status quo is Pareto efficient, and that their existence is necessary for majority-rule “chaos.” The typology also sharply separates positive from negative agenda control: division of the question threatens clown cars but never bridging vehicles. We develop all of this in the simplest possible setting—a single proposal and a single sincere vote—and indicate how it organizes the strategic analysis of agenda formation that we pursue in companion work.
Clark, Tom S. "A Model of Criminal Justice Discretion." (working paper)
Criminal prosecutors wield tremendous power in the American legal system. However, their ability to direct prosecution against criminal suspects relies on coordination with the police who investigate crimes and make arrests. That relationship has been made more prominent in the context of reform prosecutors who propose to shift traditional law-enforcement priorities. I propose a novel model of police-prosecutor interactions that focuses on the informational asymmetry between police and prosecutors. Police are endowed with private information about the true criminality of an arrested suspect but also have biases about prosecution and charges. I evaluate how prosecutors' preferences over leniency affect credible communication between police and prosecutors. Analysis of the model identifies empirical implications for the types of criminal suspects prosecuted, prosecutors' adoption of police charges, and the success rate for prosecutors who take cases to trial.
Clark, Tom S. "Coordinated Justice: The Politics of Prosecution and Policing." (working paper)
Criminal justice outcomes emerge from the coordinated actions of police and prosecutors, yet these institutions are typically studied in isolation. We lack a theoretical framework for understanding how the strategic incentives of police agencies and elected prosecutors interact to jointly determine enforcement patterns. This paper develops a game-theoretic model in which police choose evidence investment and enforcement allocation while prosecutors set evidentiary standards for charging. The analysis reveals a strategic complementarity between these choices that generates multiple equilibria, institutional path dependence, and electoral cycling in enforcement regimes. Identical formal policies can sustain sharply different enforcement environments depending on coordination history, and reforms that fail to account for this interdependence may produce null or heterogeneous effects. The framework yields direct implications for the empirical analysis of criminal justice reform, offering guidance for interpreting estimated reform effects.
Clark, Tom S. "Municipal Liability Insurance as Police Oversight: Evidence from Vallejo, California." (working paper)
Municipal liability routinely translates police misconduct into costs for local governments, yet we know little about whether liability's structure actually changes police behavior. This article studies one underappreciated mechanism: insurance. Private liability insurers can function as decentralized oversight because they price risk, impose deductibles, and provide risk-management services. When a city shifts from pooled risk-sharing to market-based coverage, the fiscal consequences of misconduct become sharper. I examine such a transition in Vallejo, California, which in 2018 left a municipal risk pool after high police liabilities and obtained market-based coverage. Using a generalized synthetic control design with monthly California data, I estimate that Vallejo's violent-crime clearances rose substantially, stabilizing at roughly 30 additional clearances per month relative to the synthetic counterfactual — on the order of a near doubling of the pre-treatment rate. This evidence suggests a shift in resources towards activities that increase the rate of crime solving, supporting the expectation that liability institutions shape ex ante incentives inside public bureaucracies, not merely compensate victims.
Clark, Tom S. "Beneath the Ballot: Drift, Discretion, and the Severity of Coercion." (working paper)
Do the officials citizens elect control the bureaucracies that act in their name, and where those bureaucracies are coercive, how does change reach them? I take the question to the prosecutor's office, assembling the Cook County enforcement funnel—arrests linked to felony review, charging, and disposition, 2014–2019—across the election of the reform prosecutor Kim Foxx. The office grew more lenient, but not through the levers our theories credit. The shift was not a break at the election and not the work of new personnel; it was a gradual, office-wide drift in how the reviewers already in place used their discretion. And it moderated coercion rather than withdrawing it: the office convicted no less often, and by plea as before, but increasingly of a lesser offense. Control over a coercive bureaucracy, this suggests, runs less through who staffs it than through the slow conversion of its incumbents' discretion.
Clark, Tom S., and John W. Patty. "Managing Intractable Problems." (working paper)
Intractable problems are inherent to governance and politics. A problem is "intractable" if it is not only difficult to agree on a solution, but also difficult to agree on what a potential solution will lead to. Intractable problems are characterized by broad and persistent low public satisfaction. We introduce two related, but distinct, notions of why reform might be pursued in a political system: complexity and complicatedness. Complexity centers on the difficulty of understanding the problem itself, and complicatedness focuses on the difficulty of making accurate decisions to mitigate the problem. We also consider how these notions are caused and/or ameliorated by having an "outsider" reconfigure the decision process, and how their presence affects the potential costs and benefits of reform by an outsider.