Ensuring sustainable transition from more to less polluting technologies has become an area of increasing interest to academics and policymakers alike over the recent years. Environmental innovations play a key role in this transition. Still, to date relatively little empirical research has been undertaken on the topic. This applies particularly to the potential impact of knowledge spillovers stemming from environmental innovation, termed here as environmental knowledge spillovers (ES), on firms’ productivity; a research gap explored in this paper. The focus is laid on three economic areas (Europe, Japan and USA), over the period 2002–2017. Additionally, firms’ technological diversity, institutional quality, corporate taxes and the stringen...