In 1979 and 1992, the Roper Organization did surveys that contained a number of questions about millionaires. For one, they handed people a card and asked people "which of these fields of work produces the most millionaires." The results (multiple responses were allowed, so they add to more than 100%).
The professions (law, medicine, architecture, etc.) 32% 46%
Business and industry 48% 48%
Government and politics 27% 35%
Labor unions 13% 10%
Agriculture 3% 3%
Entertainment 44% 51%
Sports 32% 66%
Education 1% 3%
Banking and finance 30% 30%
Organized crime 45% 50%
The biggest change between 1979 and 1992 involves sports, which isn't surprising because salaries did increase in professional sports and this development received a lot of publicity. The increase in the percent naming government and politics may reflect rising cynicism about politics. I can't think of a good reason why the professions had a large jump. People also missed one important development--the increase of high earnings in banking and finance. But the most remarkable thing to me was that 45-50% of the people named organized crime. I thought the 1979 figures were some kind of mistake at first, but that's what the numbers said.