Bank funding constraints and the cost of capital of small firms

This paper analyzes how banks' funding constraints impact the access and cost of capital of small firms. Banks raise external finance from a large number of small investors who face co-ordination problems and invest in small, risky businesses. When investors observe noisy signals about the true implementation cost of real sector projects, the model can be solved for a threshold equilibrium in the classical global games approach. We show that a "socially optimal" interest rate that maximizes the probability of success of the small firm is higher than the risk-free rate, because higher interest rates relax the bank's funding constraint. However, banks will generally set an interest rate higher than this socially optimal one. This gives rise to a built-in inefficiency of banking intermediation activity that can be corrected by various policy measures.