Can both crime and imprisonment be reduced by investing in police?

• Published date: 01 February 2019
• Author: Gary Sweeten
• Date: 01 February 2019
• DOI: http://doi.org/10.1111/1745-9133.12437

DOI: 10.1111/1745-9133.12437

EDITORIAL INTRODUCTION

MORE COPS, FEWER PRISONERS?

Can both crime and imprisonment be reduced by

investing in police?

Gary Sweeten

Arizona State University

Correspondence

Gary Sweeten,School of Criminology & Cr iminal Justice, Arizona State University,411 N. Central Avenue,MC 4420, Phoenix,

AZ85004.

Email:Gar y.Sweeten@asu.edu

After a precipitous and unprecedented 30-year climb from the 1970s to 2000s, U.S. incarceration rates

have begun a slight decline (Kaeble & Cowhig, 2018). We have yet to descend from this mountain

of mass incarceration. In fact, there is considerable debate on how to accomplish the descent and

whether it is even possible without significant increases in crime rates. In the pages of this journal

and elsewhere, the idea of shifting criminal justice resources from correctional spending to police

spending has been proposed as a way to both reduce crime via deterrence and reduce incarceration as

a by-product (Durlauf & Nagin, 2011; Kleiman, 2009).

Durlauf and Nagin (2011) appealed to the deterrence literature to support this proposed shift. Specif-

ically, after years of increasing incarceration rates, little evidence exists that additional incarceration

will result in additional deterrence; the marginal deterrence rate is negligible. On the other hand, there

is growing evidence of a significant marginal deterrent effect of police hiring. Furthermore, police can

deter crime by focusing on tactics that increase perceived certainty of punishment.

Of course, one of the main functions of police is to make arrests, so it is possible that any deterrent

effect of increased police staffing is offset by an increase in arrests and subsequent imprisonments.

As explained by Jacob Kaplan and Aaron Chalfin (2019, this issue), the expected effect of police

on incarceration chiefly depends on two elasticities with respect to police: apprehension and crime.

Simply put, if the marginal effect of police on crime (deterrence) exceeds the marginal effect of police

on apprehension, then increased police staffing will not result in increased prison commitments.

By using state-level data from 1997 to 2015, Kaplan and Chalfin (2019) present evidence on the

effect of increased police expenditures on crime, arrests, and prison commitments. These margins are

difficult to identify because of endogeneity and simultaneity issues. Kaplan and Chalfin identify these

margins using an instrumental variable strategy, comparing them with ordinary least-squares estimates.

Their instrument, fire safety expenditures, has been used previously (Kovandzic, Schaffer, Vieraitis,

Orrick, & Piquero, 2016; Levitt, 2002), and as seen previously, it does not allow for precise estimates.

Kaplan and Chalfin confirm prior estimates of the deterrence effect of police officers. They estimate

that each additional officer deters approximately seven index crimes.

Criminology & Public Policy. 2019;18:167–169. wileyonlinelibrary.com/journal/capp © 2019 American Society of Criminology 167