Thomas Piketty’s Capital in the Twenty-First Century is the most widely discussed work of economics in recent history, selling millions of copies in dozens of languages. But are its analyses of inequality and economic growth on target? Where should researchers go from here in exploring the...

This handbook chapter reviews recent developments in the theory of optimal labor income taxation. We emphasize connections between theory and empirical work that were initially lacking from optimal income tax theory. First, we provide historical and international background on labor income...