The Design of Tax Structure: Direct versus Indirect Taxation*

The recent literature on optimal taxation may be seen as attempting to clarify the structure of the arguments advanced to support changes in the tax system, tracing the implications of taxes and quantifying (analytically) the trade-offs between the various objectives of tax policy. This literature has examined the optimal structure for particular types of taxation taken in isolation, such as the optimal rates of excise tax and the optimal income tax schedule. Our purpose, on the other hand, is to provide a broader framework and to consider the interaction between different kinds of taxation. To illustrate this, we reexamine the age-old question of direct versus indirect taxation and the relationship of these taxes to the goals of efficiency, vertical equity and horizontal equity. After describing in section 2 the general framework of the analysis, and arguing that any treatment of the choice of tax structures must be centrally concerned with distributional considerations, we begin in section 3 with the extension of the classic Ramsey formula for optimal excise taxation to include vertical equity objectives. This was considered by Diamond and Mirrlees (1971), but the results