================= HES POSTING ================= Dan Bromley is right that Bator had it in 1957, as well as 1958. Wakatabe's allusion to the fact that Samuelson's "Aspects of Public Expenditure Theories" was originally presented in 1955 (details of which are in a footnote in Samuelson's paper) is worth pursuing. Unless there was some "stray" use of the term prior to the mid-to-late 1950s, it would seem that the term "externality" was coined then -- and perhaps (probably??) by either Samuelson or Bator, who were at MIT together. In terms of the general concept (as opposed to the explicit term), there is the whole "Empty Boxes" literature, Pigou's Economics of Welfare (which takes the matter beyond Marshall's cost analysis and into areas now more commonly associated with the term externality, and of course Knight's classic "Some Fallacies in the Interpretation of Social Cost." In the nineteenth century, Sidwick and Mill both do a bit to develop the concept, and Sidgwick even has a "primitive" version of the Coase theorem idea. Malthus also brings out the notion of externalities in his population essay. Steve Medema [log in to unmask] ============ FOOTER TO HES POSTING ============ For information, send the message "info HES" to [log in to unmask]