Cournot Competition and “Green” Innovation: An Inverted-U Relationship

We evaluate the relationship between competition and innovation in an industry where production is polluting and R&D has the aim to reduce emissions. We build up an oligopoly model where n firms compete in quantities and decide their investment in green R&D. When environmental taxation is exogenous, the investment in green R&D always increases with the number of firms in the industry. We analyse next the case where taxation is endougenously determined by a regulator with the aim to maximise social welfare. An inverted-U relationship exists under reasonable conditions, and it is driven by the presence of spillovers.