ABSTRACT We analyze optimal monetary policy and its implications for asset prices when aggregate demand has inertia. If there is a negative output gap, the central bank optimally overshoots aggregate asset prices (above their steady‐state levels consistent with current potential output). Overshooting leads to a temporary disconnect between the performance of financial markets and the real economy, but accelerates the recovery. When there is a lower bound constraint on the discount rate, good macroeconomic news is better news for asset prices when the output gap is more negative. Finally, we document that during the COVID‐19 recovery, the policy‐induced overshooting was large.

ABSTRACT We present a model of financial crises that stem from endogenous complexity . We conceptualize complexity as banks' uncertainty about the financial network of cross exposures. As conditions deteriorate, cross exposures generate the possibility of a domino effect of bankruptcies. As this happens, banks face an increasingly complex environment since they need to understand a greater fraction of the financial network to assess their own financial health. Complexity dramatically amplifies banks' perceived counterparty risk, and makes relatively healthy banks reluctant to buy risky assets. The model also features a novel complexity externality .