I came across this paper [PDF] that answers precisely that question.
To quote from the executive summary:
This paper presents summary statistics on the occupations of taxpayers in the top
percentile of the national income distribution and fractiles thereof, as well as the
patterns of real income growth between 1979 and 2005 for top earners in each
occupation, based on information reported on U.S. individual income tax returns.
More below the jump.
This paper is fairly technical but by no means incomprehensible to the layman. It provides a much need insight into who the folks are that are "winning the economy" and what policy prescriptions, particularly with regard to taxation, might be available to address inequality.
More from the paper:
One contribution of our paper is to present summary statistics tabulated from cross‐sectional individual income tax return data at the U.S. Treasury Department on what share of top income earners work in each type of occupation, the shares of top
incomes that are accounted for by the various occupations, mean incomes of top earners in each occupation, and how all of these have changed over selected years between 1979 and 2005. Through this method we are able to account for the occupations of almost all top earners – for example, for over 99 percent of primary taxpayers in the top 0.1 percent of the income distribution in 2004.
The second contribution of our paper is to use panel data on U.S. federal income
tax returns spanning the years 1987 through 2005, which includes information on the
occupation and industry of each taxpayer, to try to distinguish empirically the causal
impact of marginal income tax rates, which affect the incentive to earn income, from
other possible explanations for the rise in top incomes.
I think this paper makes an important contribution to the discussion of income inquality and tax policy, and I urge you to read it.
FULL DISCLOSURE: I am an alum of the institution with which one of the authors is associated, but that is the only (tenuous) connection I have with the author or his work.