Ricardo Reis of Columbia University talks with EconTalk host Russ Roberts about Keynesian economics in the classroom and in research. Reis argues that Keynesian models are a useful framework for helping undergraduates understand macroeconomic ideas of general equilibrium. More generally, Reis argues, Keynesian ideas remain influential in macroeconomic research, particularly among Neo-Keynesians. Reis discusses the lessons the economics profession and the world have learned from the Great Depression and suggests that those lessons have helped us manage the current crisis. The conversation closes with a discussion of whether economics is a science.