Publicly Provided Private Goods and Optimal Taxation when Consumers Have Positional Preferences

This paper analyzes optimal differential commodity taxation, together with optimal nonlinear income taxation, in order to deal with positional preferences. It also derives the optimal public provision of private goods both when differential commodity taxation is feasible and when it is not. It is shown that publicly provided non-positional private goods which are (possibly imperfect) substitutes for positional private goods should be used as a corrective instrument even if the tax system is optimal, i.e. even when differential commodity taxation is feasible. An exception is the special case where all consumers contribute equally much to the positional externality, in which the commodity tax constitutes a perfect instrument for internalizing the positional externality.