Actually, I'm saying that if the 200+ Americans with >$2 billion in wealth consistently generated more than 4% return on capital, then at least 50% of the top 400 earners should stay relatively the same year after year (since those with >$2 billion usually stay billionaires). The fact that only 27% have appeared more than once suggests that those with more than $2 billion in net worth are reporting returns less than 4%.
Appreciating assets don't count as income. They very well may be minimizing income while still maintaining growth. When they sell those assets, they make the list.
