Jonathan Chait addresses a pet peeve of mine: conservative writers who insist on minimizing the out-sized effect of luck on life outcomes:
[O]f course, Gates (as he has acknowledged) benefited enormously not just from his family situation but from the timing of his birth, which put him in the work force at a moment when computing technology was set to explode. If he had been born a decade or two earlier, he probably would have been an anonymous lab geek if he had followed his mathematical inclinations, or perhaps the owner of a successful grocery store chain if he had pursued his entrepreneurial instincts.
The point of Chait's post is to rebut the notion that the progressive income tax is somehow unfair by debunking the self-flattering idea -- common to wealthy right-wingers -- that the distribution of income accurately reflects the distribution of talent and motivation. I recommend reading the whole thing, since it's good. That said, I think liberals would be well served by making explicit arguments for the existence of a progressive income tax, instead of trying to justify it through reiterating the importance of chance to life outcomes. After all, even if chance is the key variable, it's still possible to say that the tax is "punishing" rich people for being lucky.
Thankfully, the progressive income tax is pretty easy to defend on its own merits. Simply put, even if wealth is the sole product of hard work, smarts and determination, it remains true that -- in addition to roads, safety, etc. -- the rich derive more from the public good than their poor or middle-class counterparts. From housing to health care to taxation, the federal government spends a huge share of money on programs that mostly benefit the well-off (the mortgage deduction, for instance). Given those benefits, it's not at all unreasonable for higher-income people to pay a greater share of their income taxes, assuming -- of course -- that you view rich people as normal people with money and not as superior genetic stock (see: Greg Mankiw, for instance).
