Police often engage in "crackdowns" on crime, which are intermittent periods of high intensity policing. This paper develops a theoretical framework for modeling police monitoring behavior and individuals' decisions to engage in crime. Within this framework, we show that there are situations where it will be optimal for a crime-minimizing police agency to engage in random crackdowns. When they occur, crackdowns also provide a way of estimating the deterrence effect of policing. We illustrate the application of the model in analyzing a speed deterrence program used by police in Belgium. In particular, we estimate the deterrence effect of additional resources spent on ticketing speeders and assess whether the current level of deterrence is socially optimal.Two features characterize our notion of random crackdowns. First, they are arbitrary, in the sense that they subject certain groups (identified by presence in a particular time or place, or by other observable characteristics) that are not notably different from other groups in criminal propensities, to higher intensity police monitoring. Second, they are publicized, i.e., those who are subjected to crackdowns are informed about them before they engage in criminal activity.
1Crackdowns are employed in a number of policing situations. Some examples include drunk driving interdiction accomplished using sobriety checkpoints, crackdowns on speeding achieved through announced greater police presence on certain highways, or crackdowns on drug trafficking aimed at particular neighborhoods.
2Criminologists sometimes rationalize the use of crackdowns by appealing to psychological theories according to which the impression created by the temporary show of force (the crackdown) is a psychological "bluff" that leads potential criminals to overestimate the risk of 1 Our definition of crackdown is different from the conventional use of the term in the literature on policing (see, e.g., Rafael Di Tella and Ernesto Schargrodsky 2002, 2004) because we require that crackdowns be arbitrary. We will return to this point when we discuss the related literature.2 For example, operation "safe streets" in Philadelphia, which puts heavy law enforcement on particular city blocks, received extensive media coverage. Other examples of crackdowns include the NHTSA campaign "You Drink and Drive. You Lose," which instituted highly visible enforcement against drunk driving. Another example is "Checkpoint Tennessee," Tennessee's statewide sobriety checkpoint program.
A Theory of Optimal Random CrackdownsBy Jan Eeckhout, Nicola Persico, and Petra E. Todd* Philadelphia, PA 19104 (e-mail: petra@athena.sas.upenn.edu). We are grateful to Larry Samuelson for useful discussions. We are also grateful to the Belgian police department for sharing the data and for their assistance in its interpretation.