So either everyone in New York City was infected, or most probably 200-400k infected in LA is an order of magnitude of wishful thinking (e.g. ~2% false positive test rate.)
So either everyone in New York City was infected, or most probably 200-400k infected in LA is an order of magnitude of wishful thinking (e.g. ~2% false positive test rate.)
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.
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.
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.
EG this from UK https://twitter.com/ONS/status/1252518098047041536