On Tuesday, the Federal Bureau of Investigation released hate crime data for last year. The main finding, which appears in the headlines of several news stories about it, was that hate crimes rose 17 percent from 2016 to 2017.

Media and activist groups often blame hate crime spikes on President Trump's divisive rhetoric; the Southern Poverty Law Center has called this "the Trump effect" and pointed to supposed surges in schoolyard bulling as evidence of such a trend. The latest FBI statistics are producing similar commentary.

"The report covers the first year of President Donald Trump's time in the White House," writes Vox's German Lopez, "and he's been repeatedly criticized, from his campaign to his presidential statements and tweets, of stoking racist sentiment, particularly against immigrants and refugees."

But as Lopez correctly notes elsewhere in his post, any talk of hate crime increases must be considered in light of a very critical detail: The overall number of law enforcement agencies reporting hate crime data also increased greatly—approximately 1,000 additional agencies contributed figures in 2017 than in 2016. This means it's not obviously the case that hate crimes are more prevalent in 2017. Maybe the government just did a better job of counting them.

This seems even more plausible when the raw totals are considered. The FBI counted 7,175 hate crimes in 2017, compared with 6,121 in 2016. That's a difference of about 1,000. If every agency reporting data for the first time in 2017 reported just one hate crime, this would account for the entire 17 percent increase.

This is the problem with counting hate crimes: The numbers just aren't that useful, given that not all police agencies participate or give accurate totals. As I noted in a previous post, Baltimore County—which represents 830,000 people—reported just one hate crime in 2016. This year, Baltimore County reported 10 hate crimes. Did incidents of hate increase tenfold in a single year? Probably not; it's likelier that the police simply submitted more reliable data this year.

As with the dubious claim that anti-Semitic hate has spiked 57 percent under Trump, the media needs to be careful about encouraging unfounded fatalism.