MODEL OF THE JURY DECISION PROCESS

• NCJ Number: 58039
• Journal: Journal of Legal Studies Volume: 8 Issue: 1 Dated: (JANUARY 1979) Pages: 141-164
• Author(s): A K KLEVORICK; M ROTHSCHILD
• Date Published: 1979
• Length: 24 pages
• Sponsoring Agency: National Science Foundation
• Corporate Author: University of Chicago
• Sale Source: Institute for Scientific Information
• Language: English
• Country: United States of America

Annotation

A MODEL OF MAJORITY PERSUASION JURY DECISIONMAKING IS PRESENTED AS A DEVICE FOR GAINING INSIGHT INTO DIFFERENCES IN THE OUTCOME REACHED AND TIME CONSUMED BY DIFFERENT-SIZED JURIES USING DIVERSE VOTING RULES.

Abstract

FOR THE MODEL, JURORS ARE ASSUMED TO COME INTO THE JURY ROOM WITH THEIR PREDELIBERATION VOTES IN MIND. THE CONCEPT OF MAJORITY PERSUASION PROVIDES A DESCRIPTION OF THE WAY THE JURY MOVES TO A VERDICT, AS OPPOSED TO THE COMPARATIVE-STATIC VERSION WHICH HAS A ONE-STEP TRANSITION FROM INITIAL VOTE TO FINAL OUTCOME. THE MODEL HAS THE VIRTUE OF BEING TESTABLE WITHOUT COMPROMISING JURY SECRECY SINCE THE RESEARCH TEST REQUIRES ONLY HISTOGRAM DATA ON THE TIME JURIES TAKE TO REACH DECISIONS IN A LARGE SAMPLE OF CASES. THE MODEL'S THEORY OF JURY DECISION PROCESS CAN BE FORMULATED IN TWO ALTERNATIVE WAYS. JURIES DELIBERATIONS OF JURIES ARE MODELED AS DISCRETE-TIME STOCHASTIC PROCESSES YIELDING ANSWERS ABOUT THE PROBABILITIES WITH WHICH JURIES SUBJECT TO DIFFERENT VOTING RULES WILL REACH DIFFERENT VERDICTS; JURIES, DELIBERATIONS ARE MODELED AS CONTINUOUS-TIME STOCHASTIC PROCESSES YIELDING EMPIRICAL PREDICTIONS ABOUT THE JURY DECISION PROCESS. IN ADDITION, THE MODEL VIEWS THE NUMBER OF JURORS WHO WOULD VOTE FOR A CONVICTION AT A CERTAIN TIME AS A TIME-HOMOGENEOUS MARKOV CHAIN; IT ASSUMES THAT THE JURY CONTINUES TO MEET AND TO DELIBERATE UNTIL A DECISION IS REACHED AND THAT ALL JURIES REACH A VERDICT, AND THAT AT ANY TIME THE PROBABILITY OF A JUROR SWITCHING HIS VOTE FROM ACQUITTAL TO CONVICTION IS AN INCREASING FUNCTION OF THE NUMBER OF JURORS WHO VOTED FOR CONVICTION ON THE PREVIOUS BALLOT. THE REVERSE EHRENFEST PROCESS MODEL IS PRESENTED AS A REPRESENTATION OF THE DYNAMICS OF MAJORITY PERSUASION AND IMPLICATIONS OF THE MODEL REGARDING NONUNANIMOUS DECISION STANDARDS ARE CONSIDERED. THIS MODEL OF JURY DECISIONMAKING OVERCOMES RESEARCH PROBLEMS WITH RESISTANT OR STUBBORN JURORS BUT MAKES NO ALLOWANCE FOR PERSONALITY DIFFERENCES OF JURORS. A MORE SOPHISTICATED MODEL NEEDS TO BE DEVELOPED TO COVER THIS VARIABLE. THE APPENDIX CONTAINS THE MODEL EQUATIONS. REFERENCES ARE PROVIDED. (DAG)