Essentially, the same applies to technology transfer (chap. For example, the cost of photovoltaics produced in Japan had halved between 1973 and 1976, but none of this improvement is evident in observed prices because it occurred prior to the installation of any demonstration units, thus cumulative installed capacity was zero. Such RD&D expenditures are a small factor in the cost improvements of technologies that have already advanced to the stage where they have found commercial niche markets and are candidates for pervasive diffusion.