This book assembles nine papers on tax progressivity and its relationship to income inequality, written by leading public finance economists. The papers document the changes during the 1980s in progressivity at the federal, state, and local level in the US. One chapter investigates the extent to which the declining progressivity contributed to the well-documented increase in income inequality over the past two decades, while others investigate the economic impact and cost of progressive tax systems. Special attention is given to the behavioral response to taxation of high-income individuals, portfolio behavior, and the taxation of capital gains. The concluding set of essays addresses the contentious issue of what constitutes a ‘fair’ tax system, contrasting public attitudes towards alternative tax systems to economists’ notions of fairness. Each essay is followed by remarks of a commentator plus a summary of the discussion among contributors.