The Wall Street Journal Imitates Me

Hmm, sounds familiar.

This is because wealthy tax filers make most of their income from investments. Such income is taxed once at the corporate rate of 35% and again when it is passed through to the individual as a capital gain or dividend at 15%, for a highest marginal tax rate of about 44.75%.

This double taxation is one reason the U.S. has long had a differential tax rate for capital gains. Another reason is because while taxpayers must pay taxes on their gains, they aren't allowed to deduct capital losses (beyond $3,000 a year) except against gains in the current year. Capital gains also aren't indexed for inflation, so a lower rate is intended to offset the effect of inflated gains.