This paper uses patent citation data to study flows of knowledge across time and across institutions in the field of energy research. Popp (2002) finds the level of energy-saving R&D depends not only on energy prices, but also on the quality of the accumulated knowledge available to inventors....

I use U.S. patent data from 1970 to 1994 to estimate the effect of energy prices on energy-efficient innovations. Using patent citations to construct a measure of the usefulness of the existing base of scientific knowledge, I consider the effect of both demand-side factors, which spur innovative...

Encouraging innovation is an important part of environmental policy. A large literature in environmental economics examines the links between environmental policy and innovation. This paper reviews recent literature on green innovation. I highlight major trends in the literature, including an...

Global climate change and other environmental challenges require the development of new energy technologies with lower emissions. In the near-term, R&D investments, either by government or the private sector, can bring down the costs of these lower emission technologies. However, the results of...