Reinventing IS-LM: The IS-LM-NAC Model and How to Use It

I have been critical of the IS-LM model in earlier posts. My paper with Konstantin Platonov fixes some of the more salient problems of IS-LM by reintroducing two key ideas from Keynes. 1. The confidence fairy is real. 2. If confidence remains depressed, high unemployment can exist forever.  My new Vox piece, coauthored with Konstantin Platonov, presents the key findings of the paper in simple language. Here are some excerpts from my VOX piece...

Larry Summers has argued that market economies may get stuck in permanently inefficient equilibria. He calls this 'secular stagnation' (Summers 2014). In this equilibrium, unemployment may be permanently ‘too high’ and output may remain permanently below potential, because private investors are pessimistic about the prospects for future growth. Our most recent research attempts to explain why secular stagnation occurs and how economic policy may be used to escape it (Farmer and Platonov 2016)

In the wake of the Great Recession, macroeconomic orthodoxy is under attack. Paul Krugman (2011) has called for a return to the IS-LM model, an approach that was developed by Sir John Hicks (1937). We are sympathetic to that call but we believe that the IS-LM model needs to be redesigned. We suggest a different way of thinking about the effect of monetary policy that we call the 'IS-LM-NAC' model. It is part of a broader research agenda ( Farmer 2010, 2012, 2014, 2016a, 2018) that studies models in which beliefs independently influence outcomes.... continue reading

Here is a link to our paper, Animal Spirits in a Monetary Economy.