I agree that NY's response was bad; but how much of the difference between NY and CA is attributable to their response, and how much to pre-existing behavioral,

I agree that NY's response was bad; but how much of the difference between NY and CA is attributable to their response, and how much to pre-existing behavioral, genetic, environmental, or other factors? California (where I am) has lower population density than NYC, lower reliance on public transit even in SF or LA, an Asian population accustomed to wearing masks, fewer black people (who seem worse hit even adjusting for socioeconomic status, for a yet-unknown reason), warmer weather. How do you know what fraction of the difference in mortality is explained by those attributes vs. the government response? I say this not to excuse sending infectious patients into nursing homes, but with the goal of recognizing the tremendous uncertainty in almost all aspects of society's management of this disease. For example, Japan seems to be doing great, with no major lockdown and testing that's missing ~80% of cases (assuming 1% IFR, their 830 deaths imply 83k cases; but they've found only 17k). I strongly suspect that the Japanese response would have brought disaster in NYC or Lombardy, but I'm not sure anyone can confidently say why.