Anti-Muslim hate crimes surged in 2015...but by how much?

Is the apparent ‘Trump Effect’ even bigger than news outlets reported?

The FBI’s annual report on hate crimes in the U.S. showed anti-Muslim hate crimes jumped sharply in 2015: over a one-year span, reported incidents rose from 154 to 257.

This news bolsters the case for a 'Trump Effect': hostility stirred up and/or channeled by the President-Elect against Muslims, Latinos, immigrants, women, transgender folks, and others. It’s consistent with data from the Southern Poverty Law Center suggesting an increase in hate incidents since the election.

Media outlets like CNN reported that anti-Muslim hate crimes had surged 67% -- the stark increase over 2014’s figure. But the real magnitude of 2015's jump may be even larger. Looking at FBI reports since 2001 (when anti-Muslim attacks peaked in the wake of 9/11), we see a large drop, then fairly stable levels:

Muslim bars w trend

There's some variation in the pre-2015 figures, but not much, and there’s no obvious pattern. While incidents in 2014 were higher than the recent average, it’s not clear that this reflects an underlying upward trend, rather than random noise. (That is, we could fit a fancy model to these data, but it'd be hard to know if it was any good.)

Comparing the 2015 figure to the recent average tells us how last year's count compares to what we might have expected. Between 2002 and 2014, the average (mean) number of reported anti-Muslim hate crimes per year was 139. Compared to that rate, 2015’s figure represents an 85% surge -- perhaps an even larger 'Trump Effect' than initially reported. 

In contrast, there wasn't a visible jump in anti-Latino hate crimes according to this dataset:

Double bar Muslim-Latino

Bear in mind, these data have plenty of limitations, some discussed here and some which I’ll address in upcoming blog posts.