Check it out:
The above maps are from a recent Lancet paper (Bollyky et al, 2023) that assessed Covid pandemic policies and their correlates across US states from Jan 1, 2020, to July 31, 2022. The authors found that states with protective mandates (ie, physical distancing, masks) were associated with lower infection rates* than states without such mandates. However, state infection rates were not associated with Covid death rates. That helps explain why California, despite statewide protective mandates and a lower infection rate, had a higher Covid death rate during the pandemic than Florida. The authors of the Lancet paper also found that mask use, whether or not state-mandated, was associated with lower infection rates but not with reduced death rates.
This all seems so counterintuitive. You don’t die of Covid unless you are infected with Covid, so why wouldn’t there be an association between infection and death rates? Answer: because the vast majority of Americans who get infected don’t die, especially if they’re under 65. According to my calculations, about .1% of Americans under the age of 65 had died of Covid by the end of 2022, mostly those in the 50-64 age range (often with comorbidities). In comparison, around 1.5% of Americans 65 and over had died.
So what accounts for the differences in state death rates? Per Bollyky et al: mostly vaccination rates.
Since getting vaccinated is especially life-saving for old people, I decided to explore state vaccination rates for this group. Here is what I found:
There’s definitely a pattern in the above charts: states with more unvaccinated seniors had higher Covid death rates, with the exception of New Hampshire. The difference between California and Florida is particularly illuminating. Almost twice as many old Californians went unvaccinated as old Floridians, roughly 10% to 5%. And yet California had imposed rather strict protective mandates during the pandemic while Florida had banned mandates and instead targeted their protective efforts towards the highest-risk groups. Assuming the main goal of Covid policies had been to reduce deaths, I would say Florida had the better approach.
The lesson here isn’t that California’s approach is wrong in general. But it was overkill (so to speak) in this particular pandemic.
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** These are standardized rates.. Per Bollyky et al, “Standardised cumulative infection rates were adjusted to approximate what the cumulative infection rate would have been if every state had the population density of the USA. Standardised cumulative death rates were adjusted to approximate what the cumulative death rate would have been if every state had the age profile and comorbidity prevalence of the USA.” Throughout this post, I’ll use “infection rate” and “death rate” as shorthand for standardized cumulative infection/death rate.
Reference:
Bollyky, Thomas J., Emma Castro, Aleksandr Y. Aravkin, Kayleigh Bhangdia, Jeremy Dalos, Erin N. Hulland, Samantha Kiernan et al. "Assessing COVID-19 pandemic policies and behaviours and their economic and educational trade-offs across US states from Jan 1, 2020, to July 31, 2022: an observational analysis." The Lancet 401, no. 10385 (2023): 1341-1360. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(23)00461-0/fulltext