Thomas Piketty (French: [tɔ.ma pi.kɛ.ti]; born 7 May 1971) is a French economist whose work focuses on wealth and income inequality. He is a professor (directeur d'études) at the School for Advanced Studies in the Social Sciences (EHESS), associate chair at the Paris School of Economics and Centennial professor at the International Inequalities Institute, which is part of the London School of Economics (LSE). Piketty is the author of the best-selling book Capital in the Twenty-First Century (2013), which emphasises the themes of his work on wealth concentrations and distribution over the past 250 years. The book argues that the rate of capital return in developed countries is persistently greater than the rate of economic growth, and that this will cause wealth inequality to increase in the future. To address this problem Piketty proposes redistribution through a progressive global tax on wealth.