alt Hacker News>it's expected that around 7,000 HN readers age 25-44, die each year
That's not true unless HN readers are a representative sample of the overall 25-44 population, which they aren't. Higher-income/SES is associated with a lower mortality rate than the overall population average.
These sort of factors all have a relatively small impact. For instance, to take it to the ridiculous extreme, billionaires live about 10 years longer than average. That sounds like a lot, but it's "only" about 10-15%. So instead of the conclusion being ~7000 dying each year, it might "only" be 6000 or whatever. It's largely inconsequential to the point. And as another point mentioned we're going to skew male which brings our life expectancy significantly lower, and probably goes a long way towards balancing out whatever socioeconomic advantage that may exist.
Whatever the exact number may be 7000 is going to be a pretty reasonable ballpark, and it's certainly orders of magnitude higher than most people would expect.