Existing models of R&D are not easily reconciled with four observable aspects of R&D: initial technologies ('ideas') need to be developed further, only a minority of initial ideas is successfully brought to the market, production and process innovations take place simultaneously (whereby,...

This essay studies the optimal timing for a firm to adopt a new process innovation in the presence of learning. A policy that has been implemented by governments throughout the world to reduce the cost level of infant industries with positive externalities, is to either subsidize the research of...

This essay studies the optimal timing for a firm to adopt a new process innovation in the presence of learning. A policy that has been implemented by governments throughout the world to reduce the cost level of infant industries with positive externalities, is to either subsidize the research of...

In this paper we analyze an inter-temporal optimization problem of a representative firm that invests in horizontal and vertical innovations and that faces a constraint with respect to total R&D spending. We find that there can exist two different steady-states of the economy when the amount of...

In many countries, inducing large-scale technological changes has become an important policy objective, as in the context of climate policy or energy transitions. Such large-scale changes require the development of strongly interlinked technologies. But current economic models have little...