One of the striking aspects of present economic theory is its disjointed nature. The two major bodies of theory, micro and macro, have only a slight relationship to one another; and it is possible, as the current practice in introductory economics courses demonstrates, to learn the one with but a passing reference to the other – or to master both, equally as well, in either of the two possible sequences. Price and quantity relationships, the heart of the micro theory, can be incorporated into macro analysis only by adding additional equations to the basic Keynesian model, and then the equations are likely to have an ad hoc empirical flavor detached from the ordinarily solid theoretical underpinnings of micro theory. The consumption and investment aggregates, on the other hand, the core of the macro theory, can be approached from a micro starting point only by derogating or ignoring the importance of many of the usual variables, and in that case the aesthetic balance of the general equilibrium system is likely to be lost. From a partial equilibrium model, the consumption and investment aggregates cannot even be derived. Micro and macro theory, then, stand as two separate bodies of analysis, with little in the way of a common perspective or a common set of variables to bind them together.

The reason for this dichotomous state of economic theory can be traced to the original Keynesian formulation.