Optimal taxation as a guide to tax policy: a survey

The purpose of this paper is to survey the field of optimal taxation. In order to provide a focus, and bearing in mind the interests of many of the readers of Fiscal Studies, the paper will concentrate on attempting to answer the question of whether, and to what extent, the literature on optimal taxation can provide guidance in the practical determination of tax policy. This focus means that the survey will be selective, and will neglect many intellectually interesting results that have not yet been developed to provide clear policy conclusions. It is an interest in tax policy that has led a number of economists to undertake research on optimal taxation, and so one might expect the link between the research and the policy-making to be clear. However, the level of abstraction of much of the research, together with the extensive use of (sometimes difficult) mathematics, has caused many policy-orientated people to discount its practical value. It is dismissed as being “academic’, with little or no practical value. For some, the mere title of the field is off-putting: how can any aspect of public policy, with all its political constraints and administrative problems, ever hope to be optimal? Particularly, how can anything as unpopular as taxation be described in such terms?