Now, a study from the UCLA School of Public Affairs and the RAND Corp. may help point the way to reversing the nation's 20-year boom in prison population while continuing the decrease in crime rates seen over the past decade.
In a paper published this week in the early online edition of Proceedings of the National Academy of Sciences, UCLA public policy professor Mark A.R. Kleiman and RAND Drug Policy Research Center director Beau Kilmer demonstrate that law enforcement agencies with limited enforcement capacity can -- by concentrating sanctions on a particular geographic area, offense or group of offenders -- exploit "tipping" effects to minimize both violations and the amount of punishment actually inflicted.
Most important, their model shows that the more credible a deterrent threat is, the more likely it is to prevent violations and the less likely it is the threat needs to be carried out, ultimately reducing the cost of crime-control and punishment.
"The United States now has both an intolerably high crime rate and an intolerable number of people in prison," Kleiman said. "The brute-force approach to crime reduction through greater severity has reached its limit. This model points the way to having less crime and fewer people behind bars."
The paper, "The Dynamics of Deterrence," draws on several examples of innovative criminal justice policy that used principles of positive feedback to reduce the number of both violations and punishments, including New York City's "zero tolerance" approach to turnstile-jumping and squeegeeing; a High Point, N.C., policy involving the identification and felony prosecution of drug dealers involved in violence in a particular area; and a program in Honolulu aimed at drug probationers that coupled increased frequency of drug testing with a credible threat from a judge that violators would be immediately punished.
Using game theory and additional simulations, Kleiman and Kilmer formulated a model of deterrent effectiveness based on three factors: the initial rate at which a rule is broken, the punishment capacity available and the probability of punishment at which a potential violator would find the risk of violation not worth taking.
When, as is generally the case, law enforcement agencies lack sufficient capacity to effectively threaten all violators of all rules, Kleiman and Kilmer suggest breaking up the universe of violators into discrete groups and concentrating pressure on one group at a time -- for example, focusing on probationers who test positive for drugs, or crack dealers involved in violent offenses.
The authors observe that by concentrating enforcement capacity in this way and effectively warning the particular group of the swift and certain punishment that will be handed down to offenders, a situation can be "tipped" from a bad, high-violation state to a good, low-violation state in which a critical mass of potential offenders is sufficiently deterred -- and remains deterred once the increased enforcement capacity is relaxed.
Thus, temporarily increasing enforcement capacity on a particular crime or group can have a lasting effect in reducing the number of offenses and the number of punishments, the authors contend.
Although drawing primarily from crime reduction efforts, this model also has applications for other situations in which authorities are faced with enforcing compliance with rules, the authors say, especially where resources are limited, including classrooms, regulatory agencies and private firms, or tax collection agencies trying to minimize cheating.
The RAND Drug Policy Research Center, established in 1989, conducts research to help community leaders and public officials develop more effective ways of dealing with drug problems. In doing so, the center brings an objective, pragmatic perspective to this often emotional and fractious policy arena. The center's goal is to provide a firm, empirical foundation on which sound policies can be built.
The UCLA School of Public Affairs, founded in 1994, incorporates the best practices in scholarship, research and teaching in the fields of social welfare, urban planning and public policy. The unique intersection of these disciplines within one school allows for academic cross-collaboration and a graduate education that values perspectives at the macro- and micro-organizational levels. Graduates of the master's and doctoral programs are well prepared to take leadership roles and effect change as practitioners, researchers and policymakers in the public, private and nongovernmental sectors. Faculty members are actively engaged in leading-edge research that addresses pressing national and regional issues, including immigration, drug policy, prison reform, low-income families and youth, health care financing, transportation, the environment, national security, economic development and an aging population.
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