Saturday, November 14, 2020

Nobody Learns Anything

The reason to have and obey lockdown rules, even if they seem extreme and inconsistent (they will be, inevitably), is to reduce the transmission of the damn disease. Even with high infection rates, individual risk and certainly individual mortality risk is still quite low! Not that low, but pretty low! The "fuck it, who cares if I get it" approach from a purely selfish perspective isn't actually insane if you're youngish.

But I have two friends and they have two friends and they have two friends...

A basic model is:

  • is the number of people each person bumps into per day.
  • s is the share of the population that has covid 
  • a is the probability of contracting covid each time you bump into an infected person
Every day there's an a*s*h chance an individual contracts covid.  The goal is to reduce h by reducing overall contacts and reduce a by increasing social distancing and wearing masks. s(tomorrow) depends on today's values of a and h and s. A more complicated model incorporates gatherings, because you don't bump into one person at a time, to look at how reducing large spreader events impacts things.

Too much MATH for my long out of grad school brain early in the morning, but it doesn't take fancy equations to understand that tiny changes to h and a (and ultimately s) can have big impacts fairly quickly (in the right or wrong direction). The purpose of lockdowns is small reductions to the frequency with which possibly infectious bouncing particles hit each other, because even those small reductions matter a lot over time.