The paper draws on Siegel (1984) to argue that, while paving the way for constitutionalizing the free market in Lochner v. New York (1905), the reproduction cost method that the Supreme Court established in Smyth v. Ames (1898) as the preferred technique for assessing the “fair value” of a business for regulatory purposes, also exposed the conventional character of any valuation exercise, against the claim of objectivity made by classical economists and traditional jurists. The inconsistency between the method and the classical laissez faire philosophy underlying the Court’s jurisprudence did not escape progressive critics of the Smyth doctrine who could argue that if “value is not a fact”, then government could legitimately use it as a policy variable to pursue different kinds of socio-economic goals.