Economic Research on Tax Rates

In a previous post I argued that a flat tax in not intrinsically fair, and that there's no reason not to tax the rich at a higher rate if it promotes the general welfare. I said those rates should be determined through economic research. There's been a couple of interesting papers lately about the optimal top tax rate that I'm reading, and although they're kind of hard to follow, there have been some good simple reviews: I liked this one and this one. The take-home message is simple though: taxes should be much more progressive than they currently are.