SENTENCING AND UNWARRANTED DISPARITY - AN EMPIRICAL-ASSESSMENT OF THELONG-TERM IMPACT OF SENTENCING GUIDELINES IN MINNESOTA

Using an interrupted time-series design, this research note analyzes t he long-term effect of Minnesota's sentencing guidelines on reducing u nwarranted disparity in sentencing outcomes that fall within their sco pe of authority. Unwarranted disparity is defined as residual variatio n not attributable to legally mandated sentencing factors. Findings su ggest that although the sentencing guidelines initially reduced dispar ity for the no prison/prison sentencing decision, inequality began to revert to preguideline levels as time passed. Further analysis reveale d that the guidelines had a permanent impact on reducing disparities i n decisions on the length of prison sentence. Overall we observed an 1 8% decline in disparity for the no prison/prison outcome and a 60% red uction in inequality for the judicial decision as to length of prison sentence. Two explanations for the reversionary trend in the no prison /prison series are highlighted.