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Crime, Time, and Punishment - An Exploration of Selection Bias in Sentencing Research

NCJ Number
98432
Journal
Journal of Quantitative Criminology Volume: 1 Issue: 1 Dated: (March 1985) Pages: 103-126
Author(s)
M S ZatZ; J Hagan
Date Published
1985
Length
24 pages
Annotation
In assessing the existence and forms of sample selection bias in sentencing discrimination research, this study examines dispositions for three samples, each selected at a different stage of the justice process, using California data on felony arrests over a 3-year period. Results indicate that research bias is introduced when only sentencing decisions are the focus of discrimination studies.
Abstract
One sample analyzed was drawn from persons convicted and sentenced to prison. The second sample contained all persons convicted, whether or not they were sentenced to prison. The third sample consisted of all persons whose cases went to the prosecutor, whether or not they were ultimately prosecuted. Legitimate and nonlegitimate influences on sentence length were investigated for each analysis. Data were obtained for all processing histories of felony arrests reaching dispositions in 1977-79. Aside from the sample selection criteria, the models tested were identical. The exogenous variables were race/ethnicity, gender, age, offense type, evidence against the defendant, offense severity, mode of disposition, number of days between arrest and disposition, and degree of crime specialization (for two or more arrests). Results indicate that bias is introduced when prosecutorial case dispositions and nonprison sentences are ignored. Also, the effects of certain exogenous variables on sentence length differ, depending on the sample selection criteria. Of these, the influence of pleading guilty rather than going to trial is particularly significant. Overall, the findings are consistent with the conclusion that earlier sentencing studies have concealed the effects of sentence bargaining because of bias in sample selection. Tabular data and 74 reference listings are provided.