The comparative static properties of the impure public good model

Abstract This paper explores the comparative static properties of the impure public good model, in which a privately acquired activity jointly produces a public and a private good. The comparative statics are expressed in terms of familiar income and Hicks-compensated price responses. Unlike the pure public good model, the impure public model can display positively sloped reaction curves even in the absence of income effects. Comparative statics involve changes in price, or income, or the contributions of others, or the proportions in which the joint products are produced. Our representation highlights the influences that make the impure public model different from the public good case.