This paper proposes a new framework for understanding financial intermediation. In contrast to previous research, we consider a setting in which intermediaries possess no inherent information processing or monitoring advantages. Instead, in an economy with overly optimistic entrepreneurs who require funding from pessimistic investors, we show that intermediaries can arise endogenously. In such a setting, only a rational intermediary will be sufficiently optimistic to find it worthwhile to invest in a technology for screening entrepreneurs' projects, and yet be pessimistic enough to use this technology. Our framework produces implications consistent with heretofore unexplained stylized facts, and conjectures which are thus far untested.

This paper solves explicitly a simple equilibrium model with liquidity risk. In our liquidity-adjusted capital asset pricing model, a security's required return depends on its expected liquidity as well as on the covariances of its own return and liquidity with the market return and liquidity. In addition, a persistent negative shock to a security's liquidity results in low contemporaneous returns and high predicted future returns. The model provides a unified framework for understanding the various channels through which liquidity risk may affect asset prices. Our empirical results shed light on the total and relative economic significance of these channels and provide evidence of flight to liquidity.