Prosecutor plea bargaining and conviction rate structure: evidence from an experiment

We present a model of plea bargaining and vary the value a prosecutor places on a conviction obtained via plea bargain relative to a conviction obtained at trial. We show that increasing the relative value of a plea bargain increases the trial penalty and decreases the severity of the equilibrium plea bargain. We report the results of an exploratory experiment which assesses this prediction in a more realistic setting, in which subjects are incentivized by conviction rates. Our treatment variable is whether convictions obtained via plea bargain are included in conviction rate calculations. Including plea bargains in conviction rates increases the number of plea offers made and increases the trial penalty, which is qualitatively in line with our predictions.