Buchanan’s constitutional political economy: exchange vs. choice in economics and in politics

Abstract

This article discusses the methodological foundations of Buchanan’s constitutional political economy. We argue that Buchanan is a constitutional economist because he is an economist or a political economist. In other words, Buchanan is a constitutional economist—he insists on the necessity of focusing on constitutions and to analyze the “rules of the social game”—because he defines economics as a science of exchange. Buchanan’s definition of economics is not only specific, it is also opposed to the definition of economics that other economists retain and, above all, opposed to the definition of economics that many public choice theorists use. The latter have, in effect, adopted the Robbins 1932 definition of economics as a science of choice that Buchanan criticizes and rejects. Buchanan’s constitutional economics can be a branch of public choice only under certain conditions.