Number of craft breweries in the US

It is a curious fact, and one that most people find out about in much the same way they find out about most things—suddenly and while reading something entirely unrelated—that the more Americans have decided to ferment hops in their garages, the fewer mail carriers have been bitten by dogs. One might suppose this inverse relationship to be a coincidence, but seven years of data suggest otherwise, which is either deeply meaningful or deeply silly, and possibly both.

Here is the thing about correlations: they are remarkably good at finding each other, even when they should have nothing to do with each other. What we are likely watching is two separate responses to the same underlying economic and demographic tide. Between 2016 and 2022, the American population shifted—more urban, more millennial, more interested in things that came in small batches and cost eleven dollars. Urbanisation brings fewer dogs per capita (it is harder to keep a German Shepherd in a studio apartment in Brooklyn), while the craft brewery boom absolutely flourished in cities. It is the same economic migration that explains both: young people moved to places where they could visit breweries on Friday night, and in those same places, mail carriers encountered fewer dogs. The effect is almost physical—imagine a single great wave of demographic change, washing across the country, pushing dog ownership toward the suburbs while pulling craft beer enthusiasm toward the cities.

So we have learned something, which is mainly that the universe will surprise you if you look at enough pairs of numbers, and that the surprise is usually hiding somewhere boringly sensible. Neither breweries nor dog bites care about each other in any meaningful way; they simply both respond to where people have decided to live. It makes you wonder what other pairs of things are moving in secret lockstep across the American landscape, entirely indifferent to one another, yet perfectly synchronized. Mail carriers and beer lovers, it turns out, are both following the same invisible map.