Asset Pricing with Heterogeneous and Constrained Investors

We analyze the joint effect of borrowing and short-sale constraints in a dynamic economy populated by two constrained investors with heterogeneous risk aversions and beliefs. We find that equilibrium prices adjust in such a way that the constraints never simultaneously bind. When the constraints are tight, we observe a regime switch behavior (discontinuities) in the risk-free rate and market price of risk at a critical state, where two equilibria exist, i.e., either constraint can be binding. Stock return volatility is the lowest at the critical state. Imposing a ban on short-sales at the same time when access to credit is restrictive or tightening borrowing during a short-sale ban can potentially move the equilibrium away from the critical state, thus increase stock return volatility rather than reducing it