ABSTRACT
From William Brock's summary and Jose Scheinkman's and Thomas Sargent's discussion of the concept of the Arrow-Debreu theory, people learned that even theories which appeal to the concept of "equilibrium" do not necessarily avoid the apparently random fluctuations in the course of time. In physics these are called "non-equilibrium" systems; a liberal education on the various meanings of the word "equilibrium" was a bracing experience for all. A physicist is reminded of the nineteenth century arguments about Boltzmann's theorem and irreversibility which, among a certain kind of purist, unfortunately persist into the present. Economics differs from biology in that foresight and game-playing exist. For instance, a whole collection of actors can suddenly and simultaneously switch strategies. A presentation by Hollis Chenery of his data on growth patterns of developing countries set the stage for much of people discussion.
