Before characterizing the optimal R&D investment of the incumbent firm, we derive the investment level that maximizes total market profits, which we will use as a benchmark in the subsequent analysis. With a slight abuse of notation, we refer to this level as the ‘efficient’ investment level, although it does not account for consumer surplus. Indeed, it is easy to see that the investment level maximizing welfare is always above the one maximizing total market profits since consumers benefit from an increase in product quality. Condition (8) guarantees that overall market profits are always larger when a startup forms. Therefore, consistently with our notation, we denote the creation of a new firm as the ‘efficient’ outcome. The corresponding efficient investment level is given by: