I made this two months ago. NYC verified at 75% of the lower bound, which solidifies the notion in my eyes that we had about 30% of the city infected in wave #1.
NYC's hospitals were ultimately NOT overwhelmed, and the excess death count of 25K per the NYT verified almost perfectly with what would have been projected at 30% of NYC infected (25,818)
I think this still precludes a second wave more severe than wave 1 in NYC. But I think it also shows that the chart I created based on Imperial College #s is actually probably a good guesstimator for cities in general and that the Imperial College estimates were actually CORRECT in their distribution of CFR amongst the population.
If that is the case, the worst case "primary wave" scenario for most locations is a death toll about 4-5X that which was seen in NYC (so 1.2-1.5% of TOTAL population). In locations where hospitals do not fail, the worst case is about 2.5X the death toll in NYC. I would consider these "upper bounds".
It should be noted above estimates are calibrated for NYC's demographics. However, New York is actually a pretty YOUNG city nationally, and not only is it young, but Manhattan literally has the 2nd lowest male obesity rate in the country behind SF.
The fact that many locations have elderly populations 50% above NYC's (proportionally) AND far heavier populations is an indicator, again IMO, that what happened in NYC could actually be on the "mild" end of the spectrum when we look back twelve months from now.
Do I think Chicago and Philadelphia will see 1% of their TOTAL populations die in the fall wave? No. Could .5% die? Yes. It could actually be higher.
The areas where 1%+ of the total population dies are likely to be smaller towns, where medical systems eventually fail and are overrun, and where large proportional populations of elderly and / or obese adults then die en-masse. In these small towns, I think there is mounting evidence to suggest we could see well OVER 1% of the population die if control is lost (as is likely in most locations EXCEPT NYC, come October).
https://www.prb.org/which-us-states-are-the-oldest/It must be said, for the demographics targeted, YES, Spanish Flu was worse in that it hit the young. But this one is way more bizarre because there is a huge segment of infected that never get sick at all. But the segment that does get sick, more may actually die vs. the demographics most impacted by Spanish Flu. There is actually a decent chance this has the potential for IFRs *worse* than Spanish Flu in very many locations, even if it is almost all old people.