There's the theory of Vitamin-D deficiency. It would make some sense given NYC's climate and time of year. In LA, people likely are exposed to the sun year round. It would be interesting to see if other respiratory illnesses exhibit a similar pattern between these two cities, as I understand Vitamin-D levels have an affect those as well.

But also, NYC is considerably more dense, so diseases spread far more rapidly. Especially so considering heavy public transit use versus, what I would say is, extreme overuse of personal vehicles.

Another option: A bunch of people will die in a few weeks.

So like the fact that most of NYC, like most of Italy, and Spain is infected because they are a more dense city than LA is lying about the data because this is backed up by data in other countries like Korea, Germany and everywhere else with similar data.

Could some of the discrepancy in regional death rates be explained by a mutation in the virus?

Honestly, it seems more likely that California's much maligned car culture has served us well in this case - ensuring many of us maintain social distance which is impossible on NYC's subway and bus system. All the positive press about governor Cuomo's leadership and handling of the crisis seems a little weird given his failure to shut-down the subways (or at least curtail a but the absolutely most urgent ridership).

> Honestly, it seems more likely that California's much maligned car culture has served us well in this case - ensuring many of us maintain social distance which is impossible on NYC's subway and bus system.

California local and state government being ahead of NY in issuing shelter-in-place orders even though NY was being harder hit even before the divergent response also makes a difference. But, yeah, the hyperdensity of the NYC metro area is a big factor.

It could.

Previous studies suggested that the strain circulating in NYC is of European origin, whereas the California strain, arriving earlier, was of Asian origin.

It's always possible that the NYC one is more fatal. We don't have data, but it is possible.

Thing is, though, at the peak, NYC was seeing a 60% positive rate on tests and is still seeing something near 30%. That pretty much guaranteed that the vast, vast majority of NY cases were not detected, and still probably are not.

(Italy is back around 5-6% again, for example)

It must be the case that a dramatic percentage of NYC is infected. Certainly not more than 100% as some oversimplified maths suggest, and likely not 80%+ that would be very comforting -- but quite likely between 30% and 45%, given the Stanford and LA studies, and the NYC testing data.

Not from, with. Also, gov’t pays a hospital out $70k for every covid death.

This "with, not from" stuff collapses when you look at 5 year averages.

EG this from UK https://twitter.com/ONS/status/1252518098047041536