When firms possess unique R & D assets such as ideas or particular researchers, and there are aggregate increasing returns to scale in R & D, then there can be several Nash equilibria involving different levels of investment in R & D. However when costless communication is possible firms may be...

This paper examines the problem of nonexistence of equilibrium in a simple search model with asymmetric information. A pure-strategy, symmetric Nash equilibrium fails to exist because adverse selection arising from steady-state considerations causes a nonconcavity in the payoff function.