We present a simple proof of the Clarke-Ledyaev multidirectional mean value inequality on smooth Banach space. As application we establish a formula for the Clarke-Rockafellar directional derivative of lower semicontinuous function

This paper reviews five striking facts about inequality across countries. As Kuznets (1955) famouslyfirst documented, inequality first rises and then falls with income. More unequal societies are muchless likely to have democracies or governments that respect property rights. Unequal societies...

Since the early 2000s, research by Thomas Piketty, Emmanuel Saez, and their coathors has revolutionized our understanding of income and wealth inequality. In this paper, I highlight some of the key empirical facts from this research and comment on how they relate to macroeconomics and to...

Since the early 2000s, research by Thomas Piketty, Emmanuel Saez, and their coathors has revolutionized our understanding of income and wealth inequality. In this paper, I highlight some of the key empirical facts from this research and comment on how they relate to macroeconomics and to...

In a growth model, rent-grabbing and free riding can give rise to inequality in productivity and firm size. Inequality among firms affects a firm's incentive to free ride or to grab rents, and, hence, the incentive to invest in research and training We follow Lucas and Prescott (1971) and...

We develop a model of international trade between two symmetric countries that features inter-group inequality between entrepreneurs and workers, and also intra-group inequality within each of those two groups. Individuals in the economy are heterogeneous with respect to their entrepreneurial...