Developing a Model of Guilty Plea Decision-Making: Fuzzy-Trace Theory, Gist, and Categorical Boundaries

The Shadow of Trial (“SOT”) theory posits that a defendant will accept a plea deal when the sentence is less than the potential trial sentence and reject a plea deal when the sentence is greater than the potential trial sentence. Despite the fact that most research on plea bargaining has included some aspect of the SOT model, it is not as useful for predicting individual plea decisions as it is for predicting plea decisions at an aggregate level. This article seeks to establish a new model for predicting case-level plea decision-making based on the Fuzzy Trace Theory (“FTT”) by conducting three studies to analyze plea-decision patterns in varying conditions. FTT theorizes that decisions are made on the basis of either verbatim or gist representations. Verbatim representations include exact information (e.g., a 5 year-sentence if convicted), whereas gist representations are less precise, more contextually-based (e.g., a relatively short sentence). The results indicated that (1) individuals were more reliant on gist representations of conviction probability rather than exact numerical representations; (2) there was wide variance in the weight individuals assigned to numerical probability; and (3)  plea acceptance rates modeled a more step-like pattern instead of a linear pattern like the SOT predicts. FTT may be a more appropriate model for predicting individual plea decisions than SOT due to its more realistic expectation that defendants will be influenced only by significant changes in probability of conviction and plea discount.

“[O]ur conceptual model and results of the three studies we report here are in keeping with existing empirical research on the effects of both conviction probability and plea discount on plea decisions, including that rates of plea acceptance are positively related to changes in POC and plea discount, that these effects are not necessarily linear, and that offers exceeding [expected value of trial] will be appealing under certain conditions.” p. 418 (internal citations omitted).