Collateral constraints widely used in models of financial crises feature a pecuniary externality: Agents do not internalize how borrowing decisions taken in "good times" affect collateral prices during a crisis. We show that agents in a competitive equilibrium borrow more than a financial...

The unconventional shocks and non-linear dynamics behind the high volatility of financial markets present a challenge for the implementation of macroprudential policy. This paper introduces two of these unconventional shocks, news shocks about future fundamentals and regime changes in global...