In this note we study the distortions in an endogenous growth model developed by Grimaud and Tournemaine (2007), where new pieces of knowledge are produced in a R&D sector and used to reduce pollution emissions. Using this model along with a realistic calibration, we conclude that the economy...

World and U.S. energy intensities have declined over the past century, falling at an average rate of approximately 1.2–1.5 percent a year. The decline has persisted through periods of stagnating or even falling energy prices, suggesting the decline is driven in large part by autonomous...