Public expenditure, risk sharing and economic growth

We develop an endogenous growth model with expanding variety in which asymmetric information frictions arise when R & D ?rms need access to external funding to ?nance their R & D investments and public expenditure affects the magnitude of hidden costs, in turn affecting the severity of asymmetric information frictions. We show that public expenditure affects growth by influencing risk sharing, thereby identifying a new channel, unlike the standard mechanism used in the literature that emphasizes the role of public expenditure in directly improving the productivity of the private sector.