Indeed if you look at the Wikipedia link I posted you'll find a section on "Avoidance of tax arbitrage between capital and labor incomes" which is exactly the problem you describe.

Incidentally, when people talk about "tax shelters" and "complicated schemes the rich use to avoid paying taxes"(1) they're mostly talking about this. Though often they don't make that as clear as they should.

1. http://www.nytimes.com/2015/12/30/business/economy/for-the-w...