University Of Chicago economist John Cochrane writes:
Intuitively, this is related to the theorem that you shouldn’t tax intermediate goods, or have tariffs for moving goods around the country. Romney’s income was taxed once, when he made it. It’s not efficient to tax it again, because he chose to save it rather than spend it immediately on an orgy of houses, private jets, and a big vacation for his extended family.
If you made money in dollars, paid taxes, then went to Canada and got $1.20 Canadian, it would make no sense to say “you made 20 cents of income, we’ll tax it.” It makes no more sense to pay taxes again on money that is moved over time. We decry that Americans don’t save enough, the Chinese, the trade deficit and so on. Well, if you want people to save more, stop taxing it.
For this reason, the U.S. Tax code has been slowly reducing the taxation of rates of return. Capital gains and dividends are now taxed less than ordinary income. IRAs, 401(k), 526, and a welter of other devices allow people to save and invest without paying taxes on the rates of return. (It would be much simpler to just eliminate taxes on rates of return, but then the lawyers and accountants would have nothing to do.) Dividends are finally taxed at the same rate as capital gains. Estate taxes have been slowly and chaotically lowered.
Full post can be found here.