Knowledge spillovers from clean and emerging technologies in the UK

The UK government has committed to increase R&D support for clean technologies in an effort to meet its net-zero target by 2050. The opportunity cost of such programs crucially depends on the value of knowledge spillovers that accrue from clean relative to other (emerging) technologies. Using patent information to measure the value of direct and indirect knowledge spillovers, we derive estimates for the expected economic returns of subsidising a particular technology field. Our method allows comparing fields by the returns a hypothetical additional subsidy would have generated within the UK or globally. Clean technologies are top-ranked in terms of within-UK returns, with Tidal and Offshore Wind showing particularly high returns. In terms of global returns, emerging technologies such as Wireless, as well as Electrical Engineering outperform Clean by a small margin. We also find that cross-border knowledge spillovers are important for all technology fields, with global return rates over ten times larger than within-UK ones. In sum, our results suggest that the opportunity cost of R&D support programs for clean innovation in the UK is low at worst.