Abstract
This article examines a thesis of interest to social epistemology and some articulations of First Amendment legal theory: that a free market in speech is an optimal institution for promoting true belief. Under our interpretation, the market-for-speech thesis claims that more total truth possession will be achieved if speech is regulatedonlyby free market mechanisms; that is, both government regulation and private sector nonmarket regulation are held to have information-fostering properties that are inferior to the free market. After discussing possible counterexamples to the thesis, the article explores the actual implications of economic theory for the emergence of truth in a free market for speech. When confusions are removed about what is maximized by perfectly competitive markets, and when adequate attention is paid to market imperfections, the failure of the market-for-speech thesis becomes clear. The article closes by comparing the properties of a free market in speech with an adversarial system of discourse.