Answer all questions in complete English sentences and use proper APA citation when appropriate
c69033
Sherman_et_al_1992_The_Variable_Effects_of_Arrest_on_Criminal_Careers.pptxThe Variable Effects of Arrest on Criminal Careers: The Milwaukee Domestic Violence Experiment (MilDVE)
Sherman, L. W. et al. (1992)
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Quick Review of the 1984 Minneapolis Domestic Violence Experiment (MDVE)
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MDVE: Minneapolis Domestic Violence Experiment
The MDVE (Sherman and Berk 1984) field experiment (conducted during 1981-1982) found arrest to be an effective deterrent against repeat domestic violence.
Main Independent Variables:
Group assignment – assigned to advise, 8 hour separation, or arrest
Police Action (delivered treatment) – assigned to advise, 8 hour separation,
or arrest
Main Dependent Variable:
Repeat Violence Over Six Months
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Sherman & Berk (1984) Caveat: Treatment Dilution and Treatment Migration
According to Angrist (2006) treat dilution occurs when subjects that are assigned to the treatment group do not receive the treatment
While treatment migration, according to Angrist (2006), refers to the occurrence of control group members receiving the treatment
Both phenomena pose a threat to internal validity of an experimental design
E.g., regarding the MDVE, non-random crossovers of those who were suppose to be advised ended up being arrested may cause those who are arrested lose comparability to the advised group – treatment migration
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Prefect Compliance Cases: 91 + 84 + 83 = 258
Treatment (Arrest) Dilution Case: 1
Simple Treatment Migration Cases: 19 + 26 = 45
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Non-compliance with random assignment Attenuated the Treatment Effect of Arrest
Do to non-compliance with random assignment significant selection bias was introduced
However, when the selection bias was controlled for the deterrent effect of arrest is even stronger than previously believed (Angrist, 2006, p. 39).
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Source: Berk and Sherman, 1984, p. 6
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Milwaukee Domestic Violence Experiment (MilDVE)
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MilDVE (1987 to 1989): A Modified Replication of MDVE
The MilDVE field experiment represents a modified replication of the Minneapolis Domestic Violence Experiment (MDVE)
The two key purposes of the MilDVE study were
(1) to examine the possible differences in reactions to arrest, and
(2) to compare the effects of short and long incarceration associated
with arrest.
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Sherman et al. (1992): Variable Effects of Arrest on Criminal Careers (MilDVE)
Sherman and Berk (1984) were concerned about concerns that the MDVE sample did not allow for the evaluation of the possibility “that for some kinds of people, arrest may only make matters” – e.g., encourage domestic violence recidivism (Sherman et al. 1992, p.139)
The current article addresses the above concern and Sherman et al. (1992) observed based on the data that
“…[t]he evidence shows that, while arrest deters repeat domestic violence in the short run, arrests with brief custody increase the frequency of domestic violence in the long run among offenders in general. The evidence also shows that, among cases predominantly reported from Milwaukee’s black urban poverty ghetto, different kinds of offenders react differently to arrest: some become much more frequently violent, while others become somewhat less frequently violent.” (p. 139)
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MilDVE Funding
United States Department of Justice. Office of Justice Programs. National Institute of Justice (86-IJ-CX-K043)
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Sampling
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Sample Design
The sample was a non-probability purposive sample of calls regarding misdemeanor domestic assault cases
Unit of observation is the individual
Calls received by the Milwaukee Police regarding misdemeanor domestic assault were screened by police officers to establish eligibility for the experiment. Eligible calls were referred to the Crime Control Institute staff, who randomly assigned one of three treatments. Selection of cases continued until 1,200 eligible cases were obtained out of 2,054 cases (ICPSR)
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Select Sample Characteristics (n = 1,200)
About 91 of the suspects were male suspects (Sherman et al. 1992, p. 145)
Blacks comprised 76% of suspects (Sherman et al. 1992, p. 145)
Around 55% of the suspects were unemployed (Sherman et al. 1992, p. 145)
31% were high school graduates (Sherman et al. 1992, p. 145)
42% were intoxicated at the time police arrived (Sherman et al. 1992, p. 145)
55% had a prior arrest record and 26% with a prior arrest for a battery against the same victim as in the presenting case (Sherman et al. 1992, p. 145)
Majority of the suspects (or 64%) were never married to the domestic violence survivor (Sherman et al. 1992, p. 145)
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Modal Reason for Ineligibility (n = 854): Absence of the Offender from the Scene (56% of the ineligibles)
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Experiment Protocol
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Random Assignment: Each Offender had Approximately a Chance for Any One of 3 Treatments
Research protocol involved 35 patrol officers in four Milwaukee police districts screening domestic violence cases for eligibility, then calling police headquarters to request a randomly-assigned disposition (ICPSR, 1994).
The three possible randomly assigned dispositions were (ICPSR, 1994):
(1) Code 1, which consisted of arrest and at least one night in jail, unless the suspect posted bond,
(2) Code 2, which consisted of arrest and immediate release on recognizance from the booking
area at police headquarters, or as soon as possible, and
(3) Code 3, which consisted of a standard Miranda-style script warning read by police to both suspect and victim.
Each domestic violence case had approximately equal likelihood of being assigned to any one of the three codes
Whether the groups were balanced on background variables was not discussed in this paper
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MilDVE Exhibits High Degree of Experimental Protocol Compliance
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Prefect Compliance Cases: 400 + 384 + 396 = 1,180 (98.3%)
Sherman et al. (1992), p. 148
7.3% (or 88 of 1,200) the randomization cases were repeat couples
Data Collection
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Data Collection: Reporting and Interviews
A battered women's shelter hotline system provided the primary measurement of the frequency of violence by the same suspects both before and after each case leading to a randomized police action (ICPSR, 1994).
Initial victim interviews were attempted within one month after the first 900 incidents were compiled.
A second victim interview was attempted six months after the incident for all 1,200 cases (Sherman et al. 1992, p.149).
The data collected consists of personal interviews and police records (Sherman et al. 1992, p.149).
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Variables
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Outcome Measures: Recidivism
The main outcome measure involved recidivism, namely, the prevalence and frequency of repeat violence by sample suspects (Sherman et al. 1992)
First, recidivism was measured by calls recorded by a Milwaukee battered women's shelter hotline system
Second, according to Sherman et al. (1992) “arrests of the suspects for repeat violence (against any victim, including the same one as in the presenting incident)”, p. 149
Third, “offense reports of repeat violence by the same suspect against the same victim” (Sherman et al., 1992, p. 149)
The above three outcome variables are from official sources and no cases are missing data
The fourth data source was on recidivism was based on interviews: “up to two face-to-face interviews conducted with the victim in each randomized case” (Sherman et al., 1992, p. 149)
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Independent Variables
Treatment Group: Full Arrest, Short Arrest and Warning
Time-at-risk refers to time during which recidivism (the outcome) could have occurred – measured as length of cohabitation after initial police encounter (cf, Sherman et al. 1992, p.150-152)
Initial deterrence: initial disinclination of the offender to reoffend after experimental police treatment (time and frequency)
Long-term escalation: prevalence of same-victim violence or the frequency of any-victim violence
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Other Covariates
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| Main Effects |
| Arrest |
| Black |
| Employed |
| High School |
| Married |
| Cohabit. > 2 (over two years of cohabiting) |
| Prior |
| LogADAYS |
| Two-Way Interactions |
| Arrest & Black |
| Arrest & Employed |
| Arrest & High School |
| Arrest & Married |
| Arrest & Cohabit |
Analysis
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Generic Research Question and Hypotheses We Need to Keep in Mind
Generic Research Question:
What is the ith main effect’s impact on the outcome measure between the three treatment groups?
Generic Null Hypothesis:
The ith main effect has the same impact on the outcome measure for each of the three treatment groups.
Generic Research Hypothesis:
The ith main effect has a differential impact on the outcome measure for at least one of the three treatment groups.
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Did Time-at-Risk Vary by Treatment Group?
More Specifically: “What are the Effects of Treatment on the Amount of Time Each Couple Spent together During the Follow-up Period?”
Using n = 882 follow-up interviews, it is observed that “there were no greater differences in time-at-risk than” would be expected by chance variation: i.e., all p-values > 0.05
So the groups did not statistically differ in time-at-risk
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Aside: Survival function
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Survival Function Basics
In our Context, the survival function is a function that gives the probability that an offender will survive (not recidivate) beyond any given specified time
The Graph of a survival function consist of (Wikipedia):
x-axis is time.
y-axis indicates the proportion of offenders surviving.
The survival function graph show the probability that an offender will survive (not reoffend) beyond time t
The survival function graph is provided by the below equation:
where: is the number of offenders at the beginning of the period
is the number of offenders reoffending at time
is the ith time period
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3
~86% of offenders who were initially arrested do not reoffend for more than 3 months
~81% of offenders who were initially warned do not reoffend for more than 3 months
The prevalence of repeat violence over time is displayed for the warning treatment and the combined arrest (short/full ) treatment for n = 1,133 person with employment data available According to Sherman et al. (1992), “[f]igure 1 shows the "survival" trend in the prevalence of repeat violence over time, with an obviously clear advantage for the arrested suspects in the early days. At about seven to nine months after the presenting incidents, however, the arrest and non-arrest curves cross over, and from there on out the arrest group does worse” (p. 153-154)
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What are the Deterrent Effects of the Respective Treatments?
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Sherman et al. (1992) Key Findings So Far (p. 156)
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Any-Victim Prevalence of Repeat Violence per 10,000
Full Arrested employed suspects
per 10,000 suspects
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10,000 arrested employed suspects produced 958 (= 5,991 – 5,033) fewer acts of domestic violence a year than warned employed suspects
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Findings So Far
“A high school education predicts a fairly weak deterrent effect of arrest, but lack of a high school education predicts a fairly strong criminogenic effect of arrest. Marriage is more powerful than education, with a marriage license enhancing the deterrent effect and its absence aggravating the adverse reaction to arrest. Contrary to our expectations, length of cohabitation goes the other way, although it is not inversely correlated with marriage. Arrest appears to make suspects more violent if they have lived with the victim for over two years than if they have not.” (Sherman et al. 1992, p.163)
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Aside: Poisson Regression
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Poisson Regression
Poisson regression is a form of a regression where the response variable is a non-negative integer values (e.g.,
count data) modeled as having a Poisson distribution.
The probability mass function of the Poisson distribution with mean µ is
, for
The explanatory variables model the mean of the response variable, .
Since the mean must be positive but the linear combination can take on any
value, we need to use a link function for the parameter µ. The standard link function is the natural logarithm.
so that
)
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Outcome or Dependent Variable: Number of Subsequent Violent Incidents
Poisson Regression
Alternatively, having a prior DV hotline report rather than not having such a report increases recidivism frequency by 84% controlling for other variables in the model
“Our interpretation of the model is that being black rather than white increases the recidivism frequency rate for the arrest group by sixty-two percent, while having a job reduces it by fifty-eight percent and being a high school graduate reduces it by forty-three percent.” (Sherman et al. 1992, p. 163)
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“between two-thirds and three-quarters of all recidivist events in the first six months are concentrated among offenders who had only one repeat event” (Sherman et al. 1992, p. 165)
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Omaha is the Most Complete Replication of MilDVE
“…the Milwaukee results suggest-but with only Omaha as a replication-the analysis of prevalence as the only outcome may obscure important consequences of mandatory arrest policies on the total amount of domestic violence in a community. Frequently rates more dearly show the escalation effects of arrest.” (Sherman et al. 1992, p. 167)
However, the frequency and prevalence results among different subgroups in the sample are consistent with the Milwaukee results
“With the exception of marriage, the differences in prevalence of officially measured repeat violence (any rearrest or new complaint, combined) go in the same directions as in Milwaukee. Three out of four indicators of marginality are associated with less deterrence and generally with some escalation.” (Sherman et al. 1992, p. 167)
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Conclusion
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Findings
“The Milwaukee domestic violence experiment finds no evidence of an overall long-term deterrent effect of arrest. The initial deterrent effects observed for up to thirty days quickly disappear. By one year later, short arrest alone, and short and full arrest combined, produce an escalation effect. The first reported act of repeat violence following combined arrest treatments occurs an average of twenty percent sooner than it does following the warning treatment.” (Sherman et al. 1992, p. 167)
“The Milwaukee experiment does find strong evidence that arrest has different effects on different kinds of people. Employed, married, high school graduate and white suspects are all less likely to have any incident of repeat violence reported to the domestic violence hotline if they are arrested than if they are not. Unemployed, unmarried, high school dropouts and black suspects, on average, are reported much more frequently to the domestic violence hotline if they are arrested than if they are not. The magnitudes of the increased domestic violence associated with arrest of the latter groups are substantial, ranging up to sixty percent. The Milwaukee findings are replicated clearly in Omaha, as well as by a more limited data set in Colorado Springs.” (Sherman et al. 1992, p. 167-168)
Sherman et al. (1992) suggest a need for other approaches to the control of domestic violence among marginalized groups (e.g., the unemployed), such as greater investment in battered women’s shelters (p. 169).
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References
Angrist (2006). Instrumental Variable Methods in Experimental
Criminological Research: What, Why, and How. Journal of
Experimental Criminology: 23, p. 23-44.
Berk, R. & Sherman, L. W. (1984). The Minneapolis Domestic Violence
Experiment. The Police Foundation Reports. April, p. 1-13.
Sherman, L. W. et al. (1992). The Variable Effects of Arrest on Criminal
Careers: The Milwaukee Domestic Violence Experiment. Journal of
Criminal Law and Criminology, Vol. 83, Issue 1, p. 137-169.
Sherman, L. R., Schmidt, J. D., Rogan, D. P. (2000). User Guide to the Machine-Readable Files and
Documentation With Codebooks (ICPSR 9966). Inter-university Consortium for Political and Social
Research.
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