The following is reproduced from "An Essay on Post-Keynesian Theory: A New Paradigm in Economics", Al Eichner and Jan Kregel's 1975 Journal of Economic Literature article. Of course, the table being a summary, all entries are highly stylized.
Aspect | Post Keynesian Theory | Neoclassical Theory |
Dynamic properties | Assumes pronounced cyclical pattern on top of a clearly discernible growth path | Either no growth, or steady-state expansion with market mechanisms assumed to preclude any but a temporary deviation from that growth path |
Explanation of how income is distributed | Institutional factors determine a historical division of income between residual and non-residual shareholders, with changes in that distribution depending on changes in the growth rate | The distribution of income explained solely by variable factor inputs and the marginal productivity of those variable factor inputs |
Amount of information assumed to be available | Only the past is known, the future is uncertain | Complete foresight exists as to all possible events |
Conditions that must be met before the analysis is considered complete | Discretionary income must be equal to discretionary expenditures | All markets cleared with supply equal to demand in each of those markets |
Microeconomic base | Imperfect markets with significant monopolistic elements | Perfect markets with all micro units operating as price takers |
Purpose of the theory | To explain the real world as observed empirically | To demonstrate the social optimality if the real world were to resemble the model |