Specialization, diversification and environmental technology life-cycle

The paper analyses whether and to what extent regional related and unrelated variety matter for the development of green technology, and whether their influence differs over the technology life-cycle. Using patent and socio-economic data on a thirty-year (1980-2009) panel of US States, our study finds that unrelated variety is a positive predictor of green innovative activities. When unpacked over the life cycle, we find that unrelated variety is the main driver of green technology development in early stages while related variety becomes more prominent as the technology enters into maturity.