An interesting note in my mind is the focus on income of which the FIRE community eventually eschews. I wonder what it would look like if there was a net worth per income data set. It may already exist, but I've only seen them separately so far.
The problem with comparative net worth data is that is is confounded so heavily with age that you really need to control for both age AND income which requires much more granular data.
The typical 18-34 year old has a net worth of only $11,200, while the typical 34-45 year old has a net worth of ~$62,000 and it increases dramatically from there.* Those are median (50th percentile) numbers. Averages are much substantially higher as there are more super rich people than people with negative millions of dollars.
*Irrelevant side note and statistical pet peeve of mine: the reported size racial wealth gap in the USA almost never controls for the effect of age on net worth and, since the median white american today is 44 and the median non-white american is 31, age has a big confounding effect on the size of the gap. The real number is plenty bad on its own, there's no reason to undermine it by trying to exaggerate the gap using bad statistical analysis.
