[T]he short answer is: some, but not enough to make a dent in the deficit. If you put a floor at their current marginal tax rate of 35%, the government would obtain $37 billion more dollars. That might sound like a lot, but it amounts to just 2.5% of the 2009 $1.5 trillion deficit (which is the red line shown). If you increase the floor to the pre-Bush-tax-cut marginal rate of 39.6%, the additional revenue grows a bit — to $66 billion, or 4.5% of the year’s deficit.
Even if you get really aggressive, it doesn’t help much. Even a tax floor for these individuals at 75% would cover less than 20% of the year’s deficit. And, of course, even most populist among us probably worries that a tax rate that high could do more harm to the U.S. economy than good. All of these calculations also assume that these wealthy individuals wouldn’t find new and creative ways to ensure that their income was shielded from very high tax rates. (They would.)
So this Buffet Rule is a great populist proposal if the president wants to score some political points, but it has little practical value. It might provide the government a little bit of additional revenue, but unless extremely aggressive, it wouldn’t make a dent in the nation’s deficit problem. To do that, you’ll need to cut entitlements and/or raise taxes much more broadly.
An honest lefty, though of course he doesn’t quite understand the negative effects kick in the moment the rate is raised and accelerate far more quickly –especially on employment– than he imagines.