This is quite a mis-representation. The total number of billionaires in 1995 = 289. Of them, 66 died. 24 of them diluted their holdings to family. This is 31% of them. Of the remaining, 126 are still billionaires. That is 43% of them. I rounded it down, but if you add them together, you see only 25% dropped out. Still a big number, but maybe some of them were spiky nasdaq 5000 of the 90s : very temporary wealth due to some reason. It seems like the odds are 80% or higher of retaining your billion dollar wealth over 2 decades.

But now that the dollar is cheap (by 1995 standards) and the billionaires aplenty, maybe we should look at 5 or 10-billionaires for our next study.

[ Edited to add: Actually you do not even need to downsize 25% to 20%. Take a 1% erosion per year and you get there anyways. So basically the odds of someone losing billionaire status were about 1% per year. Quite a low chance of failure. And quite a high chance of death in comparison.]

Thank you for the fix!

this is related to the fallacy of the top 1%. the fact of the matter is only celebrities or people who had a financial windfall makes up most of the so-called 1%. the reality is that the wealthy do not populate the top 1%. they are more likely to be found at the bottom 25% of earners as they are doing all they can to lower their tax burdens which primarily centers around eliminating their taxable income.

a better label for your stats is that it takes 20 years for a family to figure out how to hide their wealth.