"• In the wake of Booker and Gall and continuing into the Post-Report Period, the difference between the average guideline minimum and average sentence imposed widened for the federal caseload overall, indicating that the influence of the guidelines generally decreased after Booker rendered them advisory. However, this trend has not continued in the most recent years of the Post-Report Period, suggesting that the influence of the guidelines may have stabilized.
"• The influence of the guidelines continued to vary substantially depending on the type of offense throughout the Post-Report Period. As indicated by the difference between the average guideline minimum and average sentence imposed, the guidelines continued to exert a strong influence on sentences imposed in firearms and illegal reentry offenses, a more moderate influence on sentences imposed in fraud and drug offenses, and a weakening influence in non-production child pornography offenses and career offender cases.
"• Major amendments by the Commission to the drug trafficking and illegal reentry guidelines appear to have strengthened their influence during the most recent years of the Post-Report Period. The difference between the average guideline minimum and average sentence imposed for these two guidelines narrowed after the Commission reduced the Drug Quantity Table by two offense levels in 2014 and comprehensively revised the illegal reentry guideline in 2016.
"• The guidelines generally exert a greater influence on sentences imposed in cases in which judicial discretion could be meaningfully assessed. Excluding cases in which judicial discretion could not be meaningfully assessed narrowed the difference between the average guideline minimum and the average sentence imposed for the federal caseload overall, and for all but one individual offense type studied, across every time period studied. This narrowing was largely attributable to the exclusion of cases with substantial assistance departures, which resulted in an average sentence reduction of 51.8 percent. Sentence reductions for substantial assistance require a government motion and afford substantial weight to the government’s evaluation."
The Influence of the Guidelines on Federal Sentencing: Federal Sentencing Outcomes, 2005-2017. US Sentencing Commission, Dec. 14, 2020.