Measuring and Explaining Charge Bargaining

Researchers seek to explain the extent and effect of the discretion of various actors in the plea-bargaining system. Though studies of the sentenced outcome alone yield little information, those focusing upon the difference between what the defendant received as a result of the plea bargain and what he would have received if he had not pled shed light upon how individual actors may affect the process. Using plea-conviction data from 1996, 1998, and 2000, the researchers compared prosecutorial discretion across counties in Washington—which employs a strict, legislatively-mandated sentencing guideline system—and Maryland—which consults a lenient, voluntary guideline system. To estimate the difference in sentence length attributable to charge bargaining (which involves the lowering of charges in exchange for a guilty plea), the researchers calculated the difference between each defendant’s expected sentence at arraignment and predicted actual sentence. The researchers then used regression to map the results as a function of crime type and defendant criminal history. The data suggests that while the rate of charge bargaining was higher in voluntary guidelines states like Maryland, the impact on sentences was greater in presumptive guidelines states like Washington. More-structured sentencing leads to increased prosecutorial discretion, and greater discretion contributes to larger charge bargains.

“[M]easuring the difference in months of prison time determined by the charge bargain may provide a very different estimate of the discretion than is given by the rate of bargaining. Although the rate of charge bargaining was higher in the voluntary guidelines state, its impact on sentences was greater in the presumptive guidelines jurisdiction[.] . . . The dramatic difference in predictions that occurred from shifting the case characteristics cautions that distributional differences . . . can easily obscure the inferences necessary for understanding the operation of the systems.” p. 122