As Professor Emeritus Robert M. Solow remarks in the Preface, there are fashions in economic theory. In the 1970s and early 1980s, a number of theorists, starting with Barro and Grossman (1971), began to examine generalequilibrium models that included non- market-clearing exchange. The motivation for this was that prices do not move instantaneously from one fullemployment equilibrium position to another, while trade nonetheless occurs in the meantime. As my dissertation explores, allowing economic agents to buy and sell at non-market-clearing prices (or before prices have adjusted to equilibrium, if they ever do), leads to separate regimes, characterised by whether each market is a buyers’ (excess supply) or a sellers’ (excess demand) market. A macro model with three markets — two inputs, labour N and resource (energy) R, and one output Y — results in eight possible regimes, as outlined in Table 3.1 in the dissertation. An agent’s behaviour in one market may be constrained by the states of the other two markets he is trading in. These spillovers mean that the comparative statics of these regimes differ, so that it is not possible for agents in a constrained market to choose their position on a choice-theoretic supply or demand function. In a survey of New Keynesian Economics published in 1990, twelve years after this dissertation was finished, Gordon (1990) remarks that: “An interesting aspect of recent U.S. new-Keynesian research is the near-total lack of interest in the general equilibrium properties of non-market-clearing models.” In the U.S. “that effort is viewed as having reached a quick dead end after the insights yielded in the pioneering work” of Barro and Grossman (1971, 1976), building on the earlier contributions of Patinkin (1965), Clower (1965), and Leijonhufvud (1968). Gordon explains this lack of interest as the consequence of a research focus, instead, on explaining sticky wages and/or prices by combining rational expectations with maximizing behaviour at the level of the individual agent. As he puts it, “Any attempt to build a model based on irrational behaviour or sub-optimal behaviour is viewed as cheating.” U.S. theorists, he says, believed that it was premature to examine the broader theoretical considerations of