# "Covid-19 Cuts U.S. Life Expectancy by a Year in First Half of 2020, Biggest Drop Since WWII": What Exactly Does That Mean?

The headline is from NBC News, and the underlying CDC report (which has also been covered by other outlets) is here.

But I'm not sure just what this means. Under 0.2% of the U.S. population has died of COVID, even through all of 2020 and early 2021. If the average years of life lost as a result of each deaths was 10 years (see this estimate, which is focused on the first half of 2020 in the U.S.), that would itself reduce the life expectancy by just 0.02 years (0.2% of 10).

As I understand it, by now about 9% of the population has survived COVID, and even if we expect the survivors to have an average 1-year reduction in life expectancy as a result of long-term effects (but how would we know that at this point?), that would reduce the life expectancy by another 0.09 years, for a total of 0.11 years.

So where does the remaining life expectancy reduction come from? Did I do the arithmetic wrong here? Or does the great majority of the life expectancy reduction stem from other factors, such as neglected care for other illnesses stemming from the lockdown, from occasional lack of ICU beds, or something else like that (or perhaps suicides or drug overdoses stemming from the lockdown?)

Or is the CDC just projecting from the COVID deaths in the first half of 2020, assuming the death rate would remain constant going forward? Someone on a discussion list I'm on suggested that in response to my query. That seems odd, since it doesn't seem to take into account vaccination, the prospect of herd immunity being reached at some point, and the like.

I'm genuinely not sure about all this; health statistics certainly aren't my main field. But I do think there's something going on here besides just accounting for years of life actually lost to COVID during the epidemic. I'd love to hear what people who do know health statistics think about this.