The role of patent protection in (clean/green) technology transfer

Global climate change mitigation will require the development and diffusion of a large number and variety of new technologies. How will patent protection affect this process? In this paper we first review the evidence on the role of patents for innovation and international technology transfer in general. The literature suggests that patent protection in a host country encourages technology transfer to that country but that its impact on innovation and development is much more ambiguous. We then discuss the implications of these findings and other technology-specific evidence for the diffusion of climate change-related technologies. We conclude that the "double externality" problem, that is the presence of both environmental and knowledge externalities, implies that patent protection may not be the optimal instrument for encouraging innovation in this area, especially given the range and variety of green technologies as well as the need for local adaptation of technologies.