What’s Up With Food Service Employment in San Diego?

Mike Boswell tweets this morning that this is “good data for a @kdrum post”:

That is peculiar, isn’t it? Why did food service employment in San Diego plummet starting in October? I poked around a bit, and didn’t come up with anything. However, the answer is supposed to be “because they raised their minimum wage,” so I took a look at that. But it doesn’t really fit. In July 2016 San Diego raised its minimum wage to 50 cents more than the state minimum. That’s a pretty small increase to have such a significant effect, and for three months it didn’t have any effect. Food service employment didn’t turn around until October. So then I took a look at Seattle and San Francisco, two other West Coast cities that have raised their minimum wages recently. Here’s what food service employment looks like in all three places:

I dunno. San Francisco and Seattle raised their minimum wages considerably more than San Diego, and their food service employment has been fine. Combine that with the tiny size of the San Diego increase and the 3-month lag before anything happened, and the minimum wage theory seems a little iffy.

But nothing else comes to mind either. Could it be due to an outflow of undocumented workers following Donald Trump’s election? Something else unique to San Diego?