This paper discusses how the structure of the tax system affects its progressivity. It suggests a measure of progressive capacity of tax systems, based on the Kakwani index, but independent of pre-tax income distributions. Using this and other progressivity measures, the paper (i) documents a decline in progressivity over the last decades and (ii) examines the relationship between progressivity and economic growth. Regressions do not reveal a significant impact of progressivity on growth, suggesting that efficiency costs of progressivity may be small—at least for degrees of progressivity observed in the sample.

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.

This paper discusses the theory and practice of tax design to achieve an efficient and equitable outcome, i.e. in support of inclusive growth. It starts with a discussion of the key principles from tax theory to guide practical tax design. Then, it elaborates on more granular tax policy, discussing key choices in the structure of the personal income tax on labor and capital income, taxes on wealth, the corporate income tax, and consumption taxes. The paper concludes by highlighting the political economy considerations of the issues with concrete recommedtions as to how to implement tax reform.

The authors observe that consumption taxation is superior to income taxation because it does not penalize saving and investment and propose that the U.S. income tax system be completely replaced by a progressive consumption tax. They argue that the X tax, developed by the late David Bradford, offers the best form of progressive consumption taxation for the United States and outline concrete proposals for the X tax's treatment of numerous specific economic issues.

There is a growing debate on the relative merits of universal and targeted social assistance transfers in achieving income redistribution objectives. While the benefits of targeting are clear, i.e., a larger poverty impact for a given transfer budget or lower fiscal cost for a given poverty impact, in practice targeting also comes with various costs, including incentive, administrative, social and political costs. The appropriate balance between targeted and universal transfers will therefore depend on how countries decide to trade-off these costs and benefits as well as on the potential for redistribution through taxes. This paper discusses the trade-offs that arise in different country contexts and the potential for strengthening fiscal redistribution in advanced and developing countries, including through expanding transfer coverage and progressive tax financing.