Warren Buffett is not the Oracle of Public Finance

Posted by Jeffrey Brown on Feb 1, 2012

Filed Under (Finance, U.S. Fiscal Policy)

It is being reported today that Senator Sheldon Whitehouse (D-R.I.) is introducing a bill that would impose a minimum 30% tax on individuals earning more than $1 million per year.  This type of tax policy – which is essentially a new version of Alternative Minimum Tax – has been dubbed the “Buffett Rule” due to the news last year that Warren Buffet had a lower tax rate than his secretary.

Warren Buffett claims to have a tax rate of 17.4 percent.  His claim, however, is only true if one ignores one of the most basic economic principles of tax analysis: that the person who writes the check is not necessarily the same as the person that bears the economic burden of a tax.  In economics, this distinction is known as the difference between “legal incidence” (i.e., the entity with legal responsibility for paying taxes) and “economic incidence” (i.e., a measure of who really bears the economic burden of the tax).

In almost any undergraduate public finance textbook, one can find simple examples of how these concepts diverge.  For example, politicians often make a big deal of the fact that the FICA payroll taxes used to support Social Security and Medicare are split evenly between employers and employees.  But economists tend to believe that nearly all of the economic burden of the payroll tax falls on workers.  In other words, even though employers pay their share of the FICA tax, in the long-run the result is that workers are paid less than they would be paid in the absence of the tax.  Thus, it is the workers and not the firms who are truly paying the tax, in spite of how it appears.

The discussion around Mr. Buffet’s taxes – as well as the more recent discussion around the release of Governor Romney’s tax returns – has completely missed this point.  Those discussions have focused solely on the legal incidence of the personal income tax system, and have failed to think through the economic incidence of the overall tax system.

How so?  It is not uncommon for wealthy individuals like Mr. Buffett to receive much of their income in the form of dividends and capital gains.  This type of income may appear as if it is receiving “preferential” tax treatment, but the reality is that it is taxed heavily.  This is driven by the fact that corporate income is taxed at the corporate level before it is available to be paid out as dividends (or used to repurchase shares, which can lead to capital gains for investors who retain their shares).  The U.S. imposes a very high – 35% – marginal tax rate on corporate income.  Thus, if a firm earns another $1000, it pays $350 in taxes, leaving only $650 to go to shareholders.  If those shareholders are then taxed at a 15% rate, that is another $97.50 that goes to the government.  This leaves only $552.50 in the pockets of shareholders for every $1000 of pre-tax earnings that are paid as dividends.  Thus, the effective marginal tax rate on this income is more like 47.5% than it is 15%.

Of course, there are at least two important caveats to this stylized example.  First, the economics profession has simply not been able to come up with a definitive estimate of who really bears the burden of the corporate income tax.  One of the leading tax scholars of our day – Alan Auerbach of the University of California at Berkeley – wrote a terrific summary of what we know on this topic back in 2005 (the paper, which was ultimately published in the NBER Tax Policy and the Economy series, is available as an NBER working paper here.)  He notes that one of the major lessons is that “for a variety of reasons, shareholders may bear a certain portion of the corporate tax burden … thus, the distribution of share ownership remains empirically quite relevant to corporate tax incidence analysis.”  This is hardly a ringing endorsement that we should assume the entire incidence falls on Warren Buffet and other shareholders, but it is quite clear that we should not be ignoring corporate taxes when making policy statements about the fairness of the tax system.

A second caveat is that not all corporations face a 35% marginal effective tax rate.  Corporate income taxation is nothing if not a complex labyrinth of rules, exceptions, and exceptions to the exceptions.  Again, however, we know that for most corporate earnings, the rate of corporate taxation is well above zero, which is the rate it would need to be for us to feel as if we can ignore it when making statements of the kind Mr. Buffett makes.

A fellow Forbes contributor, Josh Barro, points out a number of problems with the Buffett Rule, the most important of which is that it would exacerbate the already-existing tax distortion that favors debt over equity.  If Congress wants to do this, that is their prerogative.  But we should not allow them to justify potentially bad tax policy on the basis of a naïve and misleading understanding of tax incidence.