We study the effects of aligning the incentives of national authorities through the common provision of deposit insurance in a model of cross-border banks with both endogenous risk-taking and within-group risk-sharing. Under national deposit insurance, local authorities inefficiently ring-fence resources flowing from healthy to impaired subsidiaries. A single authority responsible for a common deposit insurance fund does not ring-fence. This encourages cross-border integration, but has an ambiguous impact on banks' risk-taking. Overall, common deposit insurance increases welfare when the fundamental risk in the economy is high but otherwise can lead to excessive cross-border integration and lower welfare.

