Thomas Piketty is a French economist who works on wealth and income inequality. He is the director of studies at the École des hautes études en sciences sociales (EHESS) and professor at the Paris School of Economics. He is the author of the best-selling book Capital in the Twenty-First Century (2013), which emphasizes 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, he proposes redistribution through a global tax on wealth. (Source: Wikipedia).
The attached three-minute video explains Picketty’s hypothesis.