Nonlinear Pricing, Redistribution, and Optimal Tax Policy

This paper examines the role of nonlinear pricing by public (or regulated) utilities as a redistributive mechanism in presence of an optimal nonlinear income tax. It models an economy with many types of persons who differ in two unobservable characteristics (earning abilities and tastes). We show that nonlinear pricing does have a redistributive role; it is not a substitute for an ill‐designed tax policy. We prove, assuming separable preferences, that a person whose valuation of the public sector output is smaller than the average valuation of the population (all measured at the same consumption bundle) must face a marginal price for the good above its marginal cost. Further assuming that tastes and earning abilities are perfectly correlated, we prove that everyone must face a marginal price for the public sector’s output which strictly exceeds its marginal cost if correlation is positive. These properties provide an economic rationale for the provision of “support for low‐income consumers” as mandated by the universal service and similar regulatory policies. Finally, we show that with correlated characteristics, implementation can be achieved through two separate functions: a pricing function that depends only on the public sector output and a tax function that depends only on income.