Consider the following: A Jews-for-Jesus bulletin reports, falsely, that a Jewish woman became “a believer in the tenets, the actions, and the philosophy of Jews for Jesus.” Does this publication constitute defamation? Should defamatoriness be determined in accordance with the views of the general non- Jewish community, with those of the Jewish minority, or with a normative ethical commitment? Our Article aims to provide the answers. Part I demonstrates that the de finition of defamatoriness in common law jurisdictions is essentially empirical and distinguishes between the two leading tests—the English test and the American test. Part II.A describes the English, or general community test, whereby a statemen t is defamatory if considered so by the “right thinking members of the public at large.” Part II.B details the American, or sectorial test, whereby a statement is defamatory if considered so by a substantial and respectable minority. A third possible empirical test, whereby the defamatory potential of a statement may be tested within a small group, has not been adopted in any jurisdiction. Part III, however, demonstrates that the small group test is an economically preferable option to both the English and American tests. Part III conducts two separate economic analyses of the alternative empirical tests for defamation. First, we study the relationship between the view of the community and the views of the individuals who comprise the community. We show that the defamation cases should be decided according to the unanimity rule: A statement may be conside red defamatory only when all individuals in the relevant community consider it so. Because this rule is implausible except in the case of the small group test, it suggests that both the English and American tests lack a solid theoretical foundation. Second, we study the costs and benefits associated with the various tests and find that the American sectorial test is no longer optimal. As a result, we argue that it is preferable to adopt the small group test when deciding cases of defamation.