Do weak supervisory systems encourage bank risk-taking?

Weak bank supervision could give banks the ability to shift risk from themselves to supervisors. We use cross-border bank mergers as a natural experiment to test changes in risk and the impact of supervision. We examine cross-border bank mergers and find that the supervisory structures of the partners' countries influence changes in post-merger total risk. An acquirer from a country with strong supervision lowers total risk after a cross-border merger. However, total risk increases when the target bank is located in a country with relatively strong supervision. This result is consistent with strong host regulators limiting the risky activities of their local banks. Foreign-owned competitors could then engage in the risky projects, especially if the foreign banks' supervisors are not strong. An acquirer entering a country with strong supervision appears to shift risk back to its home country. The results suggest that bank supervisors can reduce total banking risk in their countries by being strong. (C) 2008 Elsevier B.V. All rights reserved.