“ The Organization of Economic Activity: Issues Pertinent to the Choice of Market versus Non-market Allocation”

Introduction The concept of public goods, has been developed through a process of successive refinement over a long period of tire. Yet surprisingly enough there does not seem to exist anywhere in the literature a clear general definition of this concept or the more general one of "externality." The accounts given are usually either very general and discursive, difficult of interpretation in specific contexts, or else they are rigorous accounts of very special situations. What exactly is the relation between externalities and such concepts as "appropriability" or "exclusion"?