This article demonstrates that the methodology developed by Aaron and
McGuire (1970) and Maital (1973, 1975) for estimating the distributional
implications of public goods, which has been extensively used in empirical
studies, is critically dependent on a mathematically convenient but conceptually questionable assumption that has often resulted in implausible incidence
conclusions. Specifically, the Aaron-McGuire-Maital approach assumes no
substitutability between private income and public goods, which is technically
translated into additively separate utility functions. This article reviews the
distributional implications of public goods in the light of a generalized formulation of preference indicators. The most important conclusion is that if the
assumption of separability is relaxed, the usual smooth neoclassical utility
functions will at worst imply no redistribution—but never a progressive (that is,
pro-rich) incidence outcome. Moreover, under the generalized formulation,
the critical role in deriving the benefit incidence results is played by the elasticity of substitution between private and public goods and not by the elasticity
of marginal utility of income, the importance of which is contingent on the
particular functional form employed in the analysis.