Does environmental regulation drive specialisation in green innovation?

Abstract

We examine the response of technological change to one of the major environmental regulations in the European Union (EU) – the Ambient Air Quality Directive (AAQD). Our identification strategy exploits the structure of this directive, which imposes air quality measures in regions exceeding pollutant concentration limits. We implement a quasi difference-in-differences strategy and test for the effect of environmental measures on innovation in 654 technology classes at the EU region (NUTS-2) level over the 1999–2015 period. We show that AAQD environmental measures drive the specialisation of regions in green technologies. We find a positive effect for patents in the two most prevailing green technology classes, i.e., clean energy and industrial processes, as well as evidence of spatial leakage.