Identifying causation isn’t the same as doing policy analysis

Matthew Yglesias:

A few weeks ago, for example, I found myself in an argument with a think tanker about why school absenteeism exploded during the Covid-19 pandemic. My antagonist was saying that this was part of the downside of prolonged school closures. I argued that if you look at the numbers, absenteeism soared by almost as much in the places that kept schools open — a nine percent increase in the districts with the most in-person schooling versus a 12 percent increase in the districts with the least. That three percentage point gap isn’t nothing, but it’s smaller than the gap between the poorest and the richest districts and the whitest and the least-white districts. What’s more, we know that poorer and less white districts had less in-person schooling. So it seems to me that:

  • Absenteeism rose sharply even in districts that didn’t close for the pandemic.
  • There was a larger rise in the districts that closed longer, but this is accounted for by the differential demographics. 
  • Therefore, closures per se did not have a significant causal impact on absenteeism.

Note that I say this as someone who was against school closures all along and would be happy to claim vindication on this point. I just truly don’t think they have a lot of explanatory power on the absenteeism point.