From the 1980s onward, income inequality increased in many advanced countries. It is very difficult to account for the rise in income inequality using the standard labour supply/demand explanation. Fiscal redistribution has become less effective in compensating increasing inequalities since the 1990s. Some of the basic features of redistribution can be explained through the optimal tax framework developed by J. A. Mirrlees in 1971. This Element surveys some of the earlier results in linear and nonlinear taxation and produces some new numerical results. Given the key role of capital income in the overall income inequality, it also considers the optimal taxation of capital income. It examines empirically the relationship between the extent of redistribution and the components of the Mirrlees framework. The redistributive role of factors such as publicly provided private goods, public employment, endogenous wages in the overlapping generations model and income uncertainty are analysed.

This book provides a comprehensive survey of optimal income tax theory, following the development of research strategy from the basic Mirrlees model through to its refinements, examining how optimal tax rates and the shape of tax schedules are affected by new considerations. Optimal tax theory has an important contribution to make to tax policy formation, and has become especially pertinent in recent years with the renewal of controversy over whether progressive income tax is in fact desirable or not. The author not only covers the historical background and modern formulations of the theory, but extends his discussion to consider the most important extensions of the model and the interrelation of income tax with other instruments of tax and expenditure policy.