From Alan Auerbach. He concludes:
Advances in theory and evidence have provided us with a better sense of the role that capital income taxation might play in a well-designed tax system. Even without a clear result that capital income taxation should be fully avoided, there are many obvious improvements possible, including a shift away from taxing normal returns to capital rather than all returns, reforming the base of the corporate tax and the mechanism for taxing the earnings of multinational companies, and a more careful integration of lifetime capital income taxes and wealth transfer taxes.
There are many more specific reforms not included among the three major areas covered here, notably the treatment of capital gains and owner-occupied housing. The case for reform in each of these areas is quite clear; one can make little sense of taxing capital gains as we do, only upon realization and not at all at death, and providing a nearly unlimited tax benefit for home ownership. In these cases, the difficulties reside more in the political process than in our evidence. Of course, political obstacles are also present when one considers reforms of individual capital income taxes, corporate taxes and estate taxes, but we have made progress, in our research and perhaps in the political process as well, since the days of thinking that a broad-based income tax was the main objective for tax reform.