I address this question in a new paper I’ve just posted on SSRN entitled “Explaining Sentences.” Here is the gist of the paper. Since 2005, federal judges have had increased discretion to impose sentences below the range prescribed in the federal sentencing guidelines. Since the guidelines ranges are based almost entirely on the aggravating circumstances of the crime, defendants typically argue for below-range sentences based on mitigating personal circumstances (e.g., post-offense rehabilitation, effects of extended incarceration on innocent family members, positive record of military or other community service, mental illness, physical disability, age). Some precedent, perhaps most notably in the Seventh Circuit, indicates that sentencing judges should respond to such arguments even when they choose to impose a guidelines sentence, explaining to defendants why their arguments have been rejected. Other decisions, however, indicate that the sentencing judge need do little or nothing to explain a guidelines sentence. For instance, in Rita v. United States, the Supreme Court seemed to indicate it would suffice if the sentencing judge merely acknowledged the defendant’s arguments at some point somewhere on the record.

I think decisions like the one in Rita are unfortunate. Given what is at stake–often years of a person’s life–it seems a small enough imposition to require district court judges to explain themselves in a more thorough manner. Moreover, a robust explanation requirement may help to counteract the natural tendency of busy judges (as Judge Posner puts it) just “to impose the guidelines sentence and be done with it”–a practice that threatens to undermine the Supreme Court’s rejection of mandatory sentencing guidelines three years ago.