Booms and busts: New Keynesian and behavioral explanations

Capitalism is characterized by booms and busts. Periods of strong growth in output alternate with periods of declines in economic growth. Every macro-economic theory should attempt to explain these endemic business cycle movements. In this paper I present two paradigms that attempt to explain these booms and busts. One is the DSGE-paradigm in which agents have unlimited cognitive abilities. The other paradigm is a behavioural one in which agents are assumed to have limited cognitive abilities. These two types of models produce a radically different macroeconomic dynamics. I analyze these differences. I also study the different policy implications of these two paradigms.