It is becoming common to read that antiquities without a provenance stretching back to before the 1970 adoption by UNESCO of the Convention on the Means of Prohibiting and Preventing the Illicit Import, Export and Transfer of Ownership of Cultural Property are increasingly difficult to sell because of customer concerns over possible illicit trade in the past and reduced resale prices in the future. This paper proposes the term autoregulation to describe the phenomenon, and presents the results of several quantitative analyses designed to investigate its action.