The mix of public and private research funding investments in alternative energy presents a challenge for isolating the effect of government R&D funding. Factors such as energy prices and environmental policy influence both private and public R&D decisions. Moreover, because government R&D is...

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...