Salmon: Why Capital Gains Should Be Taxed as Income
Evan Soltas does his best to answer that question with his "Defense of the Capital-Gains Loophole." Here's the meat of his argument:
Most tax breaks create distortions. The tax break for capital gains does the opposite: It reduces a distortion. Investment is really deferred consumption. Taxing consumption tomorrow at a higher rate than consumption today -- which is what a tax on investment income does -- encourages people to shift consumption forward in time, and that's inefficient.
This doesn't make a lot of sense. Firstly, investment really isn't deferred consumption. The amount of money invested, in the world, is going up over the long term, not down -- which means that once you look past the natural tidal movements of money in and out of various investment vehicles, it's reasonable to say that money, once it gets invested, stays invested. Pretty much forever. The amount of money being saved, plus the amount that the investments have grown, is nearly always going to be greater, in aggregate, than the amount of money being withdrawn for the purposes of consumption. That's the inefficient thing: money that could be cycling through the economy at high velocity is instead tied up in investment vehicles, and might not be spent for decades, if at all.
Soltas comes up with an example to show that if I invest my money today and then spend it in 10 years' time, then I'm going to end up being taxed at 50% -- a higher rate than the 40% income tax. This example is a subset of the annoying dual-taxation meme . But in any case it ignores the much bigger amount of dual taxation which goes on with regard to spent money.
If I earn money and spend it today, my spending is going to become someone else's income. If that person then pays tax on that income and spends the remainder, we'll get yet another round of income tax out of it. And so on and so forth. It's a constant high-velocity money-go-round, which is driving tax revenue all the way. By contrast, if my money is tied up in savings for a decade, it's not generating any tax revenue at all. As a result, saved money generates much lower tax revenue than spent money. At the very least, then, it should be taxed at the same rate as spent money.