NY State does not have an IFR of 0.5%. You are probably quoting Cuomo's press briefing https://www.ny1.com/nyc/all-boroughs/news/2020/04/23/governor-cuomo-daily

NY State does not have an IFR of 0.5%. You are probably quoting Cuomo's press briefing https://www.ny1.com/nyc/all-boroughs/news/2020/04/23/governor-cuomo-daily-coronavirus-update-with-first-antibody-test-results https://www.ny1.com/nyc/all-boroughs/news/2020/04/23/governo... which claims 0.5% based on this math: 15740 deaths ÷ 2700000 infected = 0.58% (they round to 0.5%) However they note that the official state death count (15740 deaths) «only indicates deaths that happened in a hospital or a nursing home, and does not include coronavirus-related deaths that occurred in a home, which means the official death count is likely higher than that official number» The true number of deaths, including home deaths, is 20759 as of the date of Cuomo's press briefing, April 24 (source: https://raw.githubusercontent.com/nytimes/covid-19-data/master/us-states.csv https://raw.githubusercontent.com/nytimes/covid-19-data/mast...) Furthermore, all the figures quoted by Cuomo were provisional, mid-study. The serosurvey actually completed on April 28 and was published here: https://www.medrxiv.org/content/10.1101/2020.05.25.20113050v1 https://www.medrxiv.org/content/10.1101/2020.05.25.20113050v... The final figures as of this date were: 22777 deaths ÷ (19450000 state population × 14.0% infected) = IFR of 0.84% It is important to take deaths as of April 28 in order to minimize right censoring. «Both the UK and NY State had a policy of sending recovering patients to nursing home» Spain and Brazil did not do this and still exhibit an IFR of 1% add per the serosurveys I referenced.