Winner-Take-All Markets: Easing the Case for Progressive Taxation

Abstract

In this article Professors McMahon and Abreu examine data on changes in the distribution of income and show that those changes increasingly reflect a winner-take-all pattern in which economic rewards are increasingly skewed toward those at the top 1% of the income distribution. These changes in the distribution of income invite a re-examination of the arguments for progressive taxation, not because they strengthen the case for redistribution, but because they reflect a market in which progressive taxation is more efficient than proportional taxation. By analyzing the data on the distribution of income and constructing a model that reflects that distribution and makes conservative assumptions about the diminishing marginal utility of money, the article shows that the classic equity/efficiency trade-off is the product of an incrementalist distribution of income. The more the distribution of income reflects a winner take-all society, the more efficient progressive taxation becomes. Thus, we no longer have to choose between equity and efficiency because in a society with a winner take-all distribution of income, progressive taxation can give us both. This project addresses the design of the rate structure only, taking as its starting point a base like the one employed by the current income tax system. Work currently in progress will consider the implications of the shifts in the distribution of income for the definition of the tax base and, specifically, for the taxation of income from capital.