This study examines the complementarity effect of combining different types of environmental corporate social responsibility (ECSR) practices on firm innovation. We apply the complementarity approach to test whether the adoption of different ECSR practices (i.e. practices for fewer materials per unit produced [materials], less energy per unit produced [energy], or decreasing environmental impact [impact]) generates super-additive effects on firms' innovation, measured by innovations type: adoption, new-to-the-market, and new-to-the-firm innovation. We use data from the Spanish Community Innovation Survey for the period 2009-2014. The results show that the best combination of ECSR practices depends on the innovation type. For innovation adoption, all possible combinations of the three practices produce super-additive effects; however, the complementarity patterns differ for new-to-the-market and new-to-the-firm innovations. For new-to-the-market innovation, energy practices appear to be a key factor in fostering innovation when combined with materials or impact practices. For new-to-the-firm innovation, the combination of these three ECSR practices shows complementarity effects. These findings provide useful insights for the design of corporate social responsibility strategies.
