the disincentives of (various) marginal tax rates

Greg Mankiw in the NYT on the disincentives with higher marginal income tax rates...

I had a similar experience with playing violin in quartets after grad school. Facing a marginal tax rate of more than 50% (including mandated union dues!), it just wasn't worth it! Mankiw goes beyond that in talking about the impact of saving, compounded interest and taxes on capital gains and estates.


An important issue dividing the political parties is whether to raise taxes on those earning more than $250,000 a year. Democrats say these taxpayers can afford to chip in a bit more. Republicans say raising taxes on those who already face the highest marginal tax rates will hurt the economy.

So I thought it might be useful to do a case study on one of these high-income taxpayers. Fortunately, I have one handy: me. As a professor at Harvard and the author of some popular textbooks, I am comfortably in the income range that would be hit by this tax increase....

First, I have to acknowledge that the Democrats are right about one thing: I can afford to pay more in taxes....Indeed, I could go so far as to say I am almost completely sated. One reason is that I don’t aspire for much more than a typical upper-middle-class lifestyle....

Nonetheless, as Republicans emphasize, taxes influence the decisions I make. I am regularly offered opportunities to earn extra money....I acknowledge that my motives in taking on extra work are partly mercenary....to put some money aside for my three children...

Suppose that some editor offered me $1,000 to write an article....If I invested it in the stock of a company that earned, say, 8 percent a year on its capital, then 30 years from now, when I pass on, my children would inherit about $10,000.

...assuming that the Bush tax cuts expire, I would pay 39.6 percent in federal income taxes on that extra income. Beyond that, the phaseout of deductions adds 1.2 percentage points to my effective marginal tax rate. I also pay Medicare tax, which the recent health care bill is raising to 3.8 percent, starting in 2013. And in Massachusetts, I pay 5.3 percent in state income taxes, part of which I get back as a federal deduction. Putting all those taxes together, that $1,000 of pretax income becomes only $523 of saving.

And that saving no longer earns 8 percent. First, the corporation in which I have invested pays a 35 percent corporate tax on its earnings. So I get only 5.2 percent in dividends and capital gains. Then, on that income, I pay taxes at the federal and state level. As a result, I earn about 4 percent after taxes, and the $523 in saving grows to $1,700 after 30 years.

Then, when my children inherit the money, the estate tax will kick in. The marginal estate tax rate is scheduled to go as high as 55 percent next year, but Congress may reduce it a bit. Most likely, when that $1,700 enters my estate, my kids will get, at most, $1,000 of it.

HERE’S the bottom line: Without any taxes, accepting that editor’s assignment would have yielded my children an extra $10,000. With taxes, it yields only $1,000. In effect, once the entire tax system is taken into account, my family’s marginal tax rate is about 90 percent. Is it any wonder that I turn down most of the money-making opportunities I am offered?

By contrast, without the tax increases advocated by the Obama administration, the numbers would look quite different. I would face a lower income tax rate, a lower Medicare tax rate, and no deduction phaseout or estate tax. Taking that writing assignment would yield my kids about $2,000. I would have twice the incentive to keep working.

Now you might not care if I supply less of my services to the marketplace — although, because you are reading this article, you are one of my customers. But I bet there are some high-income taxpayers whose services you enjoy....

Reasonable people can disagree about whether and how much the government should redistribute income. And, to be sure, the looming budget deficits require hard choices about spending and taxes. But don’t let anyone fool you into thinking that when the government taxes the rich, only the rich bear the burden.