Buchanan on externalities: An exercise in applied subjectivism

Buchanan's work on the methodology of economics includes many references to externalities. Buchanan has emphasized that a subjective conception of economics, and a focus put on exchange rather than on choice, has implications on an analysis of externalities. In this paper, we analyze the reverse claim: Buchanan's views on externalities are a perfect illustration of his plea for subjectivism in economics, and the need to focus on economics-as-a-science-of exchange. We show that Buchanan's treatment of externalities was a “laboratory” for his claims and arguments about subjectivism.