The wonderful Zeynep Tufekci¹ continues to sharpen our understanding about what’s actually happening with the virus, this time with a very clear and lucid piece about why all distribution is not equal. It’s looking like COVID-19 spreads non-uniformly via “overdispersion”:

There are COVID-19 incidents in which a single person likely infected 80 percent or more of the people in the room in just a few hours. But, at other times, COVID-19 can be surprisingly much less contagious. Overdispersion and super-spreading of this virus are found in research across the globe. A growing number of studies estimate that a majority of infected people may not infect a single other person. A recent paper found that in Hong Kong, which had extensive testing and contact tracing, about 19 percent of cases were responsible for 80 percent of transmission, while 69 percent of cases did not infect another person. This finding is not rare: Multiple studies from the beginning have suggested that as few as 10 to 20 percent of infected people may be responsible for as much as 80 to 90 percent of transmission, and that many people barely transmit it.

The entire piece is worth pouring another cup of tea to dig into. The analogy of Jeff Bezos walking into a bar and suddenly the average net worth of the bar is over a billion dollars is stark, as is the comparison to deterministic infections like influenza. Our global response systems aren’t prepared to fight “stochastic disease patterns” that behave seemingly at random rather than in linear and predictable patterns.

Or “the mean is not the message”.