NCJ Number
67384
Date Published
1977
Length
4 pages
Annotation
PART OF A PILOT PROJECT TO PREDICT FUTURE INMATE POPULATIONS, THIS STUDY COMPARES ACTUAL TIME IN PRISON WITH SENTENCE LENGTH AND OFFENSE TO DETERMINE WHICH IS MORE CORRELATED WITH ACTUAL TIME SERVED.
Abstract
THE PRISON POPULATION IS SEEN AS A FUNCTION OF 3 FACTORS--ADMISSIONS, TIME SERVED AND RELEASES. IN ORDER TO FIND THE BEST VARIABLE THAT WOULD PREDICT TIME SERVED, TWO VARIABLES WERE SELECTED AS CRITERION VARIABLES (LENGTH OF SENTENCE AND OFFENSE). MULTIPLE REGRESSION WAS USED TO TEST WHICH VARIABLE WAS THE BEST PREDICTOR OF TIME SERVED AND TO TEST THE CORRELATION. ACTUAL TIME SERVED WAS COMPUTED BY SUBTRACTING THE INMATE'S RELEASE DATE FROM HIS ADMISSION DATE. LENGTH OF SENTENCES REPRESENTED THE MAXIMUM SENTENCE LENGTH THAT WAS IMPOSED ON THE INMATE BY THE COURT. A TOTAL OF 12 OFFENSES WERE SELECTED TO REPRESENT THE INMATE POPULATION AND THE SPECIFIC OFFENSE TYPES CAPTURED APPROXIMATELY 90 PERCENT OF THE PRISON POPULATION. 3 REGRESSION EQUATIONS WERE COMPUTED: ACTUAL TIME SERVED WITH SENTENCE LENGTH AND OFFENSE FOR TOTAL INMATE RELEASES FROM 1972-73 THROUGH 1975-76; ACTUAL TIME SERVED WITH SENTENCE LENGTH AND OFFENSE FOR 1975-76 INMATE RELEASES; AND A CORRELATION BETWEEN ACTUAL TIME SERVED AND OFFENSE FOR 1975-76 INMATE RELEASES. FINDINGS SHOWED THAT SENTENCE LENGTH IS MORE CORRELATED WITH ACTUAL TIME THAN WITH OFFENSE. WITH RESPECT TO PREDICTING FUTURE INMATE RELEASES, OFFENSE CAN BE EXCLUDED FROM PROJECTION MODELS SINCE SENTENCE LENGTH IS MORE CORRELATED WITH ACTUAL TIME SERVED. THIS WOULD IMPLY A SIMPLE MODEL TO PROJECT INMATE RELEASES. HOWEVER,A MORE ACCURATE ESTIMATE OF INMATE RELEASES MIGHT BE GENERATED, IF SENTENCE LENGTH AND OFFENSE WERE USED ON THE SAME EQUATION. THERE IS A NEED FOR FURTHER RESEARCH ON WHETHER A REGRESSION EQUATION BASED ON SENTENCE LENGTH PREDICTS ACTUAL TIME SERVED BETTER THAN ONE BASED ON SENTENCE LENGTH AND OFFENSE. (MJW)