Transcript Desistance and Legitimacy: Effect Heterogeneity in a Field

Desistance and Legitimacy: Effect
Heterogeneity in a Field Experiment
on High Risk Groups
Jeffrey Fagan
Andrew Papachristos
Danielle Wallace
Tracey Meares
American Society of Criminology
St. Louis
November 2008
Background
• PSN as demand-side intervention designed to reduce
gun carrying and gun use
• Recent policy preferences lean toward specific
deterrence and forced compliance: intensive costbased strategies of close surveillance coupled with low
threshold interventions to incapacitate offenders.
– Risk increase by changing police surveillance strategies to
focus on weapons and intensifying parole and probation
supervision
– Cost increase by threat of federalizing gun crimes
• Longer sentences, higher conviction rates with tougher plea
negotiations
• PSN combines applies alternate strategy to engage offenders
in more complex rational choice calculus where elevated risks
and costs of offending are offset by simultaneous increases in
the benefits of compliance and crime avoidance.
– Federal prosecution for gun crimes
– Longer sentences
– Gun-focused policing and seizures
– Serious offers of social, economic and other human
services in group dynamic (forums)
• Providing capital to high risk groups in resource-starved
neighborhoods is designed to legitimate legal sanctions in
context-neutral forums that clarify and promote more
balanced deterrence signals
• Designed for and implemented in two Chicago neighborhoods
with very high homicide and gun crime rates.
Assignment
Groups
• Guns and Homicides are
not randomly distributed
PSN Beats
• Treatment
– 24 beats on West Side
Control Beats
• Control:
– 30 beats on South
side
ATF Gun Seizures
0 - 15
16 - 31
32 - 48
49 - 67
68 - 117
Moran’s I = .378 , p =.001
Research Design
• Quasi-Experimental Panel Design
– Near-equivalent Control Group
– Panel data of every “neighborhood” in Chicago from
1999 to 2006
– Multi-level modeling strategy to assess within and
between group variation in neighborhoods
– Neighborhood and individual data
• Data
– Multiple sources – CPD, ATF, IDOC, and the Census
– Crime reports geocoded to police beat
– Quarterly from January 1999 to December 2006
– Individual data reported by zip code (!@#*)
Neighborhood Results
• Strong declines in homicides in target areas compared
to control areas and citywide rates
• No evidence of displacement to adjacent police
districts
– We use propensity scores to adjust for differences in target
and control areas as well as secular trends in the city
– Declines evident in both homicide and other gun crimes
• Compared to other PSN components, the number and
saturation of PSN forums exerts the strongest influence
on recidivism rates
• Aggregate effects on social networks of gun offenders?
Aggregation produces generalized effects (general
deterrence) via social influence model?
2.5
3
Figure 4. Fitted Model Summary with 95 % CI
2
PSN Beats
1
1.5
Control Beats
0
5
10
15
quarter
20
25
Results 1. Summary of PSN
Neighborhood Effects
Homicides
(logged)
Gun Homicides
(logged)
Gang Homicides
(logged)
Aggravated
Battery
(logged)
PSN (Dummy)
Coeff
Exp(B)
SE
p-value
-0.052
0.949
0.013
0.000
-0.053
0.948
0.013
0.000
-0.011
0.989
0.008
0.235
-0.012
0.988
0.008
0.159
Percent Offenders
Attend Forum
Coeff
Exp(B)
SE
p-value
-1.17
0.310
0.528
0.026
-0.782
0.457
0.431
0.072
-0.951
0.386
0.285
0.001
-0.063
0.939
0.193
0.744
PSN Predictor
Results 2. Summary of PSN
Neighborhood Effects
Prosecutions
(logged)
Person-Month
Sentences
(logged)
Aggravated
Battery
(logged)
Homicides
(logged)
Gun Homicides
(logged)
Coeff
-0.002
-0.002
-0.00009
0.003
Exp(B)
0.998
0.998
1.000
1.003
SE
0.001
0.001
0.0007
0.003
p-value
0.075
0.042
0.894
0.325
Coeff
-0.031
-0.024
-0.017
0.007
Exp(B)
0.969
0.976
0.983
1.007
SE
0.017
0.017
0.011
0.007
p-value
0.075
0.150
0.128
0.368
Coeff
-0.003
-0.003
0.002
-0.02
Exp(B)
0.997
0.997
1.002
0.980
SE
0.005
0.005
0.003
0.002
p-value
0.658
0.943
0.490
0.298
PSN Predictor
ATF Seizures
Gang
Homicides
(logged)
Recidivism Effects
• Methods and Data
– Criminal history data on 3,092 ex-offenders from
experimental and control Chicago police districts
– Analyzed over four years to assess differences in
timing of recidivism
– Cox regressions
– Disaggregated to examine separate effects on
gang and non-gang members and first offenders
versus repeat offenders
– Disaggregate by type of crime
• Propensity Scores ?
• Cox Models
– S (t) = Pr (T > t)
– Overlapping risks, neither competing nor
exclusive
– Covariates
•
•
•
•
•
•
Race – African American
Age – years
Education – High school graduate
Family ties – Married or cohabitating
Prior record – first offense
Gang member
Sample
Comparison
PSN
Total
N
2,677
(100)
415
(100)
3,092
(100)
Male
2,635
(98.4)
407
(98.1)
3,042
(98.4)
African American
2,531
(94.5)
383
(92.3)
2,914
(94.2)
Age (mean)
35.1
35.0
35.1
Married or Cohabitating
208
(7.8)
18
(4.4)
226
(7.3)
Prior Arrest
1,185
(44.3)
277
(66.7)
1,462
(47.3)
Gang Member
1,297
(48.4)
91
(21.9)
1,388
(44.9)
Any Recidivism
950
(35.5)
67
(16.1)
1,107
(35.8)
PSN Effects: Within-District Comparisons
Offense Category
Non-Gang
Gang
All Crimes
-1.547
(.38)
-.839
(.20)
Murder
-43.74
(.005)
-.287
(1.01)
Total Violent Crime
-.350
(.58)
-.006
(.36)
Property-Violent
-.424
(.80)
-1.467
(.66)
Drug Sales
-.193
(.71)
-.145
(.23)
Drug Possession
-.355
(.37)
-.145
(.23)
Weapon
-46.07
(.005)
.113
(.39)
Drug Conspiracy
.000
(1.52)
1.643
(.97)
PSN Effects: Between-District Comparisons
Offense Category
Non-Gang
Gang
All Crimes
-1.649
(.40)
-.795
(.19)
Murder
54.81
(1.00)
-.276
(1.00)
Total Violent Crime
.290
(.61)
.404
(.37)
Property-Violent
.649
(.086)
-.563
(.54)
Drug Sales
-.225
(.68)
.110
(.35)
Drug Possession
-.936
(-.586)
-.586
(.22)
Weapon
-36.36
(.37)
.123
(.37)
Drug Conspiracy
-34.56
(1.52)
2.001
(.91)
PSN Effects: Between-District Comparisons –
First Offenders versus Priors
Offense Category
Repeaters
First Offenders
All Crimes
-.945
(.18)
-37.29
(.19)
Murder
-.559
(1.03)
-36.94
(1.01)
Total Violent Crime
-.070
(.31)
-34.27
(.44)
Property-Violent
-.987
(.50)
Drug Sales
-.392
(.33)
Drug Possession
-.106
(.20)
Weapon
-.357
(.38)
Drug Conspiracy
-1.643
(.097)
-41.88
(.30)
.000
(.00)
Next Steps
• Competing risk hazards model
• More detail on prior records
• Temporal analysis to estimates effects of
degrading of intervention
• Contemporaneous neighborhood change