Comparative statics for the private provision of normal and inferior public good

Abstract

This paper studies a standard model of the private provision of public goods under the assumption that the public good is either normal or inferior for every consumer at every level of wealth. Using new tools from monotone comparative statics, we show that the condition of normality (inferiority) of public good is sufficient for the extremal total equilibria contributions to be increasing (decreasing) with the number of consumers. The lattice-theoretic methodology we use also allows us to generalize the classic existence result by showing that the assumption of quasi-concavity of the utility function is not ``critical’’ and therefore can be relaxed.