Teaching Keynes’s principle of effective demand within the real wage vs. employment space

This paper reviews several models for teaching Keynes’s principle of effective demand with a special focus on a framework that is familiar to advanced undergraduate students of macroeconomics: the real wage vs. employment space. It is argued that existing approaches to teaching Keynes’s principle of effective demand reflect a tension between two goals: being true to Keynes and translating the effective-demand principle into a story about real wages and employment within a single graphical space. Our main contribution consists of presenting an extended version of a model originally proposed by Lavoie (Rev Radic Polit Econ, 35(2):166–182, 2003), which seems to be a reasonable compromise between these two goals.