Optimal Policing, Crime, and Clearance Rates

• Date: 01 August 2016
• Author: Steven Raphael
• DOI: http://doi.org/10.1111/1745-9133.12236
• Published date: 01 August 2016

POLICY ESSAY

DIRECTIONS IN DETERRENCE THEORY

AND POLICY

Optimal Policing, Crime, and Clearance

Rates

Steven Raphael

University of California, Berkeley

In a recent article published in Criminology, Nagin, Solow, and Lum (2015) (herein

referred to as NSL) presented a model of criminal offending whereby criminal op-

portunities are heterogeneous in their apprehension probability and where those who

offend rationally prefer opportunities with low apprehension risk. The model is intended to

provide a broad framework for thinking about the findings from three literatures: deterrence

research, research on the relationship between policing (both staffing levels and strategies)

and crime, and the environmental and criminal opportunities research that emphasizes the

situational factors that give rise to criminal opportunity and victimization. In doing so,

the model emphasizes the dual role of police: as sentinels that proactively protect against

criminal victimization through deterrence and as reactive investigators of realized crime.

Aside from the formal modeling of how crime and clearance rates are jointly determined,

as well as the implications thereof, the article also articulated a social objective function

that one might argue should serve as the guiding objective for policing practice: namely,

minimizing the social costs associated with crime and punishment. A key implication of

the model is that policing that concentrates enforcement efforts on criminal opportunities

with high potential for deterrence (a concept that I will elaborate on shortly) will yield both

reductions in victimization and punishment levels. A secondary implication of this model is

that such efficient use of policing may lower clearance rates, suggesting that clearance rates

provide a poor and inaccurate measure of police performance and the risk of apprehension

(a point first discussed by Cook [1979]).

In this issue, Justin Pickett and Sean Roche (2016) critique the NSL (2015) model

based largely on the propositions that (a) there is no evidence that the offending behavior

of potential offenders is sensitive to objective variation in apprehension risk and sanction

Direct correspondence to Steven Raphael, Goldman School of Public Policy, University of California, Berkeley,

2607 Hearst Avenue, Berkeley, CA 94720-7320 (e-mail: stevenraphael@berkeley.edu).

DOI:10.1111/1745-9133.12236 C2016 American Society of Criminology 791

Criminology & Public Policy rVolume 15 rIssue 3