An Explicit Test of Plea Bargaining in the “Shadow of the Trial”

Bargaining in the “shadow of the trial,” which hinges on the expectations of trial outcomes, is the primary theory used by noncriminologists to explain variation in the plea discount given to defendants who plead guilty. This study develops a formal mathematical representation of the theory and then presents an empirical test of the theory using an innovative online survey with responses to a hypothetical case from 1,585 prosecutors, defense attorneys, and judges. The key outcomes are the probability that the defendant will be convicted at trial, the sentence for the defendant if convicted, and the best plea that the respondent would accept or offer. Variation in the outcomes is created through experimental variation in the information presented to the respondents. Structural regression models are estimated to fit the formal theoretical models, and the instrumental variables method is used to correct for measurement error in the estimate for probability of conviction. The data support the basic shadow model, with minor modifications, for only prosecutors and defense attorneys. Controlling for the characteristics of the individual actors and their jurisdictions adds explanatory value to the model, although these control variables did not affect the key coefficients from the shadow model.