How far an Austrian law and economics should be Posnerian? A comment on Peter Leeson Alain Marciano Published online: 18 July 2012 # Springer Science+Business Media, LLC 2012 Abstract The purpose of this note is to stress that Posner ’ s conception of law and of the role of judges in a legal system might be problematic for an Austrian approach to law and economics, despite the praxeological dimension of his analysis. Keyword Posner . Austrian economics . Law and economics . Economic analysis of law . Constructivism . Judges . Common law JEL Codes B53 . K00 . K49 In “An Austrian approach to law and economics, with special reference to superstition”, published in this review, Peter Leeson develops an argumentation about ” what an Austrian law and economics must be” or “what the components of an “Austrian” law and economics might consist of” (2012, p. 1). Leeson’ s paper is made of two parts. The second one focuses on the role that certain individuals’ beliefs-in that case, superstitions, that is “objectively false beliefs”—play in the emergence of rules or institutions and in their functioning. In other words, the second part of the paper examines how important for legal systems beliefs are. Such an approach is not only presented by Peter Leeson as an instance of Austrian Law and Economics but also a form of economic analysis of law à la Richard Posner. The connection between Richard Posner and Austrian economics is made in the first part of the paper, where Peter Leeson compares Ronald Coase’ s and Richard Posner ’ s conception of economics and of law and economics, explains that “Ronald Coase’ s conception of law and economics precludes” the analysis of phenomena that are central to Austrian economics while”Richard Posner’ s facilitates it” (Leeson 2012, p. 3) and concludes that “[a]n Austrian law and economics can’t be built on Coasean foundations. But it can and should be built on Posnerian ones.” (p. 3; emphasis added). Rev Austrian Econ (2012) 25:351–354 DOI 10.1007/s11138-012-0185-5 A. Marciano (*) Université Montpellier 1, UMR5474 LAMETA, F-34000 Montpellier, France e-mail: alain.marciano@univ-montp1.fr