It is commonly argued that in recent years pharmaceutical companies have directed their R&D towards small improvements of existing compounds instead of more risky drastic innovations. In this paper we show that the proliferation of these small innovations is likely to be linked to the lack of...

I study the relation between the delay in the transmission of spillovers of information and diffusion. When a firm enters or innovates it benefits from the information it gets by observing past entry. Delays in the process of receiving the information reduce the benefits of the spillover and...