How can one defend the 1% ?

In a forthcoming article in the Journal of Economic Perspectives1, Harvard Professor and bestselling textbook author Greg Mankiw defends the income earned by the richest 1%, as opposed to the movement of the 99% that attacks the explosion of inequality and the concentration of income and wealth. Mankiw cites the study by Thomas Piketty and Emmanuel Saez (2003, updated 2011)2, which shows that in the United States the share of income earned by the richest 1% rose from 7.7% in 1973 to17.4% in 2010. Mankiw argues that the income received by the 1% is fair and denounces the idea of taxing them at what he considers confiscatory rates. He criticizes in particular the proposal of French President François Hollande to tax high income at a marginal rate of 75%, in the following terms: “using the force of government to seize such a large share of the fruits of someone else’s labor is unjust, even if the taking is sanctioned by a majority of the citizenry”. To defend this position, Mankiw uses a theory of justice based on “just deserts”. According to this perspective, people should receive compensation in proportion to their contributions. If the economy were described by a classical competitive equilibrium without externalities or public goods, then every individual would earn the value of his or her own marginal product, and there would be no need for government to redistribute. In this perspective, equity isperfectly aligned with the right incentives.