The breakdown of the IS–LM synthesis: implications for post-Keynesian economic theory

The monetarist and the new classical economics attack routed the IS–LM version of Keynesian theory and the large scale econometric models from the centre of macroeconomic research. However monetarism and the new classical economics were more successful as a critique of the IS–LM orthodoxy than as a basis for fruitful research and policy analysis.

Post-Keynesian economists also attack the IS–LM orthodoxy, mainly because it misspecified ‘… the economic society in which we actually live’. Post-Keynesians that emphasized financial and labour markets argued that properties of the real world economy made instability normal results ofmarket interactions.

The vacuum in main line theory that developed as the shortcomings of monetarism became evident led to a revival of interest in basic Keynesian propositions. This has spawned what is now labeled a new Keynesian economics. New Keynesian economists conform to the modeling standards set by the new classical rational expectations school but claim to get Keynesian results. To a degree these results are compatible with propositions of post-Keynesian economics.

It is suggested that a convergence between the new and the post-Keynesian economics can be expected, and the result is likely to be fruitful.