Small isolated theories can be restated as choice and exchange theory; in effect, incorporating them into the theory. The procedure employed is to state the implicit or explicit propositions of the small theories in ordinary language, then restate and extend them. (Author)

Contrary to assumptions of the supergame model, agents in exchange situations will normally not be perfectly informed about past behavior of their partners. Moreover, they will generally be in a position to choose their partners. The formal model of this article, reputation formation, attempts to take account of these facts. (JBJ)