Pedestrian traffic fatalities

It appears that Americans have discovered a direct metabolic pathway between intestinal wellness and vehicular catastrophe, which suggests either that probiotics are terrifyingly ineffective at their stated purpose, or that the more we worry about our insides, the less we watch where we're going. Between 2005 and 2022, as we collectively spent an additional billion dollars on live bacterial cultures, pedestrians kept getting hit by cars with almost supernatural consistency. One begins to suspect the universe enjoys a joke about misdirected attention.

What's likely happening here is that both metrics are simply riding the same economic tide. Population growth explains much of it—more people means more pedestrians in crosswalks and more affluent consumers buying the small expensive bottles of cultured liquid that promise digestive serenity. Add in the rise of health anxiety as a leisure activity, the expansion of consumer spending during the 2010s boom, and the simple fact that cars got more numerous while sidewalks stayed put, and you've got two separate trends that move together the way two swimmers might both drift downstream without ever actually touching. The probiotic market grew from roughly $15 billion to $60 billion globally during this window, roughly the same period when more Americans owned vehicles than sense.

This is what happens when you feed a pattern-recognition algorithm two datasets that happen to exist in the same country during the same years—it finds a waltz where there is only coincidence. We are pattern-seeking creatures living in an absurdly complex world, which makes us either scientists or conspiracy theorists depending on whether we check our work. The correlation between dead pedestrians and probiotic sales tells us almost nothing except that we are very good at moving in tandem with modernity. Neither variable cares about the other.