Evan Soltas
Dec 18, 2015

The First Count

An unofficial count of the number of anti-Muslim hate crimes since the Paris and San Bernardino attacks is now available, and it looks like my and Seth's model got it right.

Updating the search data to the most recent week, the model estimates there were about 37 hate crimes against Muslims since the Paris attacks. There were 38. And the model estimates there were about 16 hate crimes against Muslims since San Bernardino. There were 18.

Had anti-Muslim sentiment been at normal levels, there would have been about 8 and 4 respectively, so the model did a remarkable job getting right the magnitude of the deviation from normal. These were all "out-of-sample" forecasts -- that is, none of our estimates were made including the last month of data.

A few caveats. First, the model's performance is unusually accurate this time. It's better to expect us to miss by about five to ten hate crimes or so in future surges like this one, rather than being off by one or two. The model leaves more unexplained than this single performance would suggest. Second, this is an unofficial count; as we said in the article, we will be waiting until year-end 2016 for the official numbers, which might be different.