Uniform pricing and social welfare

We re-examine the case for uniform pricing in a monopolistic third-degree price-discrimination setting by introducing differentiated costs. A profit-maximizing monopolist could then use price differentiation to reduce the production of the more costly goods, thereby decreasing average cost and increasing welfare. Indeed, monopolistic price differentiation can improve welfare and also aggregate consumer surplus even if, as in the benchmark linear case, total output does not increase. Accordingly, the welfare criterion based on total output fails and should be replaced by the computation of well-defined price indexes. These results possibly pave the way for a more optimistic assessment of monopolistic pricing.