Proactive Policing and Robbery Rates across Large U.S. Cities:

Assessing Robustness

Charis E. KubrinGeorge Washington University

Steven F. MessnerGlenn Deane

Kelly McGeeverState University of New York, Albany

Thomas D. StuckyIndiana University-Purdue University

Indianapolis

Aims of Current Study

• To replicate Sampson and Cohen (1988)

• To expand their model specification

• To explore the possible implications of endogeneity

Explanations for Discrepant Findings on Policing and Deterrence

• Police work is not devoted to crime reduction

• Police practices do not affect arrest certainty

• Displacement of offenders

• Methodological issues:– Limitations with arrest certainty measures– Nature of causal relationship between police

strength and crime rates

Proactive Policing and Crime

• Indirect effect of proactive policing on crime through arrest risk– Increasing arrest/offense ratio

• Proactive policing may directly affect crime rate by influencing community perceptions regarding the probabilities of apprehension for illegal behavior– Public disorder

Specifying a More Complete Model

• Index of concentrated disadvantage– Poverty, family disruption, joblessness

• Role of local politics– Wilson (1968) Varieties of Police Behavior– Policing styles: watchman, legalistic, service– Elected mayors, partisan elections, district

based council representation

Data and Methods

• Sample: U.S. cities with pop. of 100,000+ with at least 1,000 blacks in 2000 (n=181)

• 5 data sources: (1) counts of robberies known to police and city pop. totals; (2) yearly arrest counts for DUI and disorderly conduct; (3) police employee data; (4) demographic data from 2000 census; (5) two databases on political system characteristics of city governments

Data and Methods Contd.

• Dep. vble= robbery offenses known for all cities that were available in UCR for 4-yr. period: 2000-03– Smoothed data

• Key Indep. vble= proactive policing– Sum of # arrests for DUI and disorderly

conduct / # sworn police officers– Lagged measure of proactive policing using

data for 4-year period (1996-99) immediately preceding period of interest

• Indep. vble= robbery arrest/offense ratio– Lagged measure

Data and Methods Contd.

• Controls: city pop size (logged), median family income, % divorced, % non-Hisp. Black, racial income inequality, dummy vble. for West location

• Model extension:– Resource deprivation: % poverty, % non-Hisp. Black,

% unemployed, % high school grad, % female-headed households, median family income

– Residential instability, % young males– City political system characteristics

• 3 elements: (1) mayor-council forms of government, (2) council members represent specific geographic areas, and (3) city elections are partisan

Table 1. Regressions of Certainty of Arrest and Robbery Rates.

Certainty of Arrest

(log) Robbery RateModel I

(log) Robbery RateModel II

b b b

Intercept .587* - 3.773* - 1.732* -

(log) Proactive Policing -.002 -.013 -.132* -.125 -.142* -.135

(log) Population -.026* -.171 .203* .200 .200* .198

Percent Divorced -.006 -.097 -.004 -.011 .049* .127

Western Location -.009 -.039 .258* .165 .075 .048

Racial Inequality .003 .010 .238* .122 .291* .150

Median Income (in $1000s)a .002* .223 -.033* -.512 - -

Percent Non-Hispanic Blacka -.002* -.253 .018* .396 - -

Resource Deprivation Index - - - - .538* .690

Traditional Government Index

- - - - .036 .044

Percent Young Males - - - - .214 .005

Percent Moved - - - - .308 .024

R-Square .229 .757 .746

*Statistically Significant for a Two-Tailed Test at the .05 Levela Incorporated in the "Resource Deprivation Index" for Model II of Robbery Rates

Table 2. Non-Recursive Models of the Police Measures and Robbery Rates.

(log) Robbery RateModel 1

(log) Robbery RateModel 2

b b

Intercept1.735

*- 3.624* -

(log) Proactive Policing-.129

*-.142 -.103* -.098

(log) Population .201* .199 .139* .137

Percent Divorced .048* .124 .025 .066

West .075 .048 .117 .075

Racial Inequality .294* .152 .311* .160

Resource Deprivation Index

.541* .694 .464* .595

City Politics Index .036 .043 .065 .079

Percent Young Males .099 .002 -1.804 -.040

Percent Moved .276 .021 -.321 -.025

Certainty of Arrest - - -1.833* -.274

* Statistically Significant for a Two-Tailed Test at the .05 LevelModel 1 = 2SLS with lagged Proactive Policing as instrumentModel 2 = 2SLS with lagged Proactive Policing and lagged Certainty of Arrest as Instruments