Risk shifting and regulatory arbitrage: Evidence from operational risk

We document a robust negative relation between operational risk exposure and bank capital levels for a sample of large U.S. banks under the Basel I Capital Accords. The results are consistent with the notion that capital-constrained banks increased operational risk exposure at the time when Basel I regulations did not require an explicit capital charge for operational risk. More broadly, our results show new channel by which financial regulations incentivize banks to shift their risk taking to less regulated risk areas. We focus on the case of operational risk because it went from a largely unregulated risk type to a major risk that accounts for about 25% of large U.S. banks’ risk-weighted assets.