A protester in New York City last week. Photo: Kena Betancur/AFP/Getty Images

African-Americans suffer a disproportionate risk of being shot dead by police. While white Americans make up 62 percent of the U.S. population, they account for only 49 percent of those killed by cops over the past year and a half, according to the Washington Post. For black Americans, those figures are 13 percent and 24 percent, respectively. What’s more, the Post found that unarmed African-Americans were five times as likely as unarmed white Americans to be fatally shot by police.

However, it’s also true that African-Americans experience a disproportionate number of encounters with law enforcement. And a new study from Harvard suggests that, within the context of police encounters, cops are no more likely to shoot black civilians than white ones.

Economist Roland G. Fryer, the youngest African-American to receive tenure at Harvard, launched the study in response to the police killings of Michael Brown and Freddie Gray.

“You know, protesting is not my thing,” Fryer told the New York Times. “But data is my thing. So I decided that I was going to collect a bunch of data and try to understand what really is going on when it comes to racial differences in police use of force.”

Fryer’s study is based off detailed police reports from ten major police departments in Texas, Florida, and California. He and his student researchers examined 1,332 shootings between 2000 and 2015, and attempted to isolate race as a variable. Which is to say, they sorted police shootings by context — i.e. “at the scene of robbery,” “at night,” “after being attacked by suspect,” etc. … — and looked at whether cops were quicker to fire at black civilians, when controlling for those contexts.

Fryer calls the results of this inquiry the “most surprising” of his career: The study found no significant evidence of racial bias when controlling for context, and showed that officers were actually more likely to shoot suspects who hadn’t attacked them when those suspects were white.

These findings are a valuable contribution to our understanding of race and policing in America, but they should be ingested with a few grains of salt:

1. The results rely, in part, on the accuracy of police reports. Such reports have been contradicted by video recordings in some of the highest-profile fatal police shootings of the last few years.

2. The cities examined are not demographically representative of the country as a whole. Most of the municipalities have a larger-than-average population of African-Americans. It’s possible that in jurisdictions where the black population is smaller, and thus less politically powerful, police use lethal force in a more racially biased manner.

3. Most critically, the study does not address the way racial bias determines who gets stopped by police in the first place. While African-Americans do commit a disproportionate rate of the nation’s violent crimes, this does not fully account for the rate at which police stop them. African-American drivers are 31 percent more likely to be pulled over by police than are white drivers, according to Justice Department statistics. This is not due to a disproportionate affinity for speeding among the black community — whites are actually more likely to be pulled over for exceeding the speed limit, while black drivers are flagged at a higher rate for vehicle defects and record checks. African-Americans are also twice as likely to be pulled over for no explicit reason whatsoever.

The Justice Department’s investigation into Ferguson, Missouri, found that the city’s police department enforced the law in a manner designed to maximize revenue rather than public safety. In other words, the department aggressively policed petty crimes in the city’s black community so as to generate enough fines to keep the government running. In Ferguson, police didn’t disproportionately stop black residents because of their higher rate of violent crime, but because of their lower level of political power. (A mayor that directed police to aggressively shake down wealthy white residents would be unlikely to retain office.) As Jack Hitt wrote in Mother Jones last year, the Ferguson PD is far from the only department in the nation to overpolice black communities for fiscal responsibility’s sake. For African-Americans, the cost of funding local government in this manner is measured in more than dollars and cents.

Racial discrepancies in the use of force were considerably starker in the reports of civilians rather than officers. In a nationally representative survey, Fryer found that black people were 170 percent more likely to have been grabbed by police; 87 percent more likely to have been kicked, Tased, or pepper-sprayed; and 305 percent more likely to have had a gun pointed at them.

Fryer’s study concludes by noting the potentially corrosive psychological impact such treatment may have on African-American youth: