Economist Thomas Sowell looks at people in the top one percent of income and finds that group is transient. An excerpt:
At the highest income levels, people are especially likely to be transient at that level. Recent data from the Internal Revenue Service show that more than half the people who were in the top one percent in 1996 were no longer there in 2005.
Among the top one-hundredth of one percent, three-quarters of them were no longer there at the end of the decade.