While research indicates that sentencing guidelines systems often reduce sentencing disparity, few studies have examined whether sentencing guidelines shift discretion and disparity from judges to prosecutors. Some critics assert that guidelines do shift judicial discretion to prosecutors, but empirical evidence is scarce. This study seeks to provide some empirical data on the underresearched topic of hydraulic displacement of discretion. Using data from the District of Columbia Superior Court, the study asked whether charge bargaining practices changed after the District of Columbia adopted a regime of sentencing guidelines. The analyses indicate that some changes in the plea bargaining process did occur after the guidelines were implemented but that most were not statistically significant. Policy implications of the displacement thesis and the current findings are discussed.

There is little empirical research to indicate whether the introduction of sentencing guidelines displaces discretion from judges to prosecutors. In the handful of studies that examine the hydraulic displacement of discretion, discretion is usually measured by the rate of charge bargaining. The current study uses an alternative methodology—calculating the value of the bargain—to examine the effect of sentencing guidelines on prosecutorial discretion in the District of Columbia Superior Court. It measures the impact of charge bargaining on sentence length in a sample of 266 pre-guidelines sentences and 263 post-guidelines sentences, and finds that the rate of charge bargaining did not change after the introduction of guidelines, but that the impact of bargaining on sentence length increased slightly. Although the amount of displacement of discretion in the D.C. Guidelines was modest, the study demonstrates that alternative measures (value of the bargain) might reveal displacement of discretion when traditional measures (rate of the bargain) do not.