If you’re convicted of a federal offense, on average you will serve more time — for the exact same crime — if you’re black than if you’re white.

That’s the conclusion of a new report by the US Sentencing Commission, which found that black men got 19.1 percent longer sentences for the same federal crimes as white men between fiscal years 2012 and 2016. This was after accounting for several variables, including criminal history, whether someone pleaded guilty, age, education, and citizenship. A separate analysis that controlled for a history of violence — but only for fiscal year 2016, due to a lack of data for other years — produced similar results.

Based on the commission’s report, this disparity has grown over time.

So what’s going on here? Racial bias could very well be an answer.

The Sentencing Commission published similar reports in 2006, 2010, and 2012 to evaluate the effects of United States v. Booker in 2005 and Gall v. United States in 2007. In both cases, the US Supreme Court effectively gave federal judges more discretion in sentencing — and that discretion could lead to more opportunities for racial bias.

According to the commission’s report, judges are less likely to cut black men a break than white men. White men were more likely to get their sentences reduced under the judge’s discretion than black men, and white men got larger reductions than the ones black men got.

As Christopher Ingraham noted at the Washington Post, this likely wasn’t the only explanation. A 2014 study published by the University of Michigan Law School, for example, found that prosecutors’ initial charging decisions were a major driver of racial disparities in sentencing: All else held equal, black arrestees were 75 percent more likely to face a charge with a mandatory minimum sentence than white arrestees. (Even for the same crime, prosecutors often have a variety of charges they can file.)

Behind both of these examples, though, is discretion that can be driven by racial bias.

Several studies have found that race plays a powerful role in how the general public — and, by extension, those in the criminal justice system — see people. A recent series of studies published by the American Psychological Association, for example, found that people are more likely to see black men as larger and more threatening than white men, even if the black men are not actually larger. Another study published in the Journal of Personality and Social Psychology in 2014 found that people are more likely to view black children 10 years and older as “significantly less innocent” than their white counterparts.

This helps explain how skin color can predict the length of someone’s punishment and other racial disparities in police shootings, the harshness of speeding tickets, punishments for car crashes, arrests for drug crimes, clearance rates for murder investigations, and more.

There could be other factors. As the Sentencing Commission acknowledges, it’s possible that its analysis could be missing variables — “because a particular factor is unknown, or because data about it is not readily available.” For example, the report doesn’t have data for employment history or family circumstances, both of which could influence a judge’s sentence. As a result, the commission said its report “should be interpreted with caution and should not be taken to suggest discrimination on the part of judges.”

Still, other research suggests that racial bias plays a significant role in the US criminal justice system — and the Sentencing Commission’s report provides more proof in that direction.