Probability and punishment: How to improve sentencing by taking account of probability

The United States Sentencing Guidelines place little emphasis on probability. Instead, the Guidelines recommend a sentence in each case based only on whether certain facts about the offender's crime exceed a "threshold" level of likelihood. Guidelines sentences therefore fail to reflect the precise odds of each defendant's wrongdoing, which makes them both inefficient and unfair. This model of decision making is particularly problematic in drug sentencing, where judges often impose lengthy sentences based on drug quantity calculations that carry a high risk of error. To address these problems, district courts should exercise their discretion, and policymakers should implement reforms that incorporate probability into punishment.