Beggar-thy-neighbour in macroprudential policy? This paper studies the impact of macroprudential policies – specifically OSII buffers – on banking groups and their cross-border operations. Using granular data from three confidential databases, we present the first evidence on how banking groups respond to changes in capital requirements. Our findings reveal that: (i) consolidated parent banks constrained by OSII buffers cut back on debt and equity holdings in their foreign subsidiaries, altering global financial structures; (ii) subsidiaries with reduced funding and equity from their parent show a notable decline in lending to non-financial corporations; and (iii) overall, cross-border subsidiaries of OSII-constrained banks exhibit reduced lending and risk-taking towards non-financial corporations, hinting at a role of these subsidiaries in propping up the group’s consolidated capital buffers. While higher capital buffers enhance financial stability by curbing excessive risk-taking, they also constrain the funding and lending capacities of foreign subsidiaries, disrupting local credit markets and creating a “beggar-thy-neighbour” problem. Policymakers need to balance these impacts with the benefits of financial integration.

We investigate the impact of capital requirements on bank lending across institutional sectors, focusing on their transmission channel and the interaction with monetary policy. By employing confidential loan-level data for the euro area, we find that the reaction of banks to capital surcharges for Other Systemically Important Institutions (O-SII) depends on the level of the required buffer and the institutional sector of the borrowing counterpart. Tighter requirements correspond to stronger lending contractions with targeted banks curtailing their lending mostly towards credit institutions. Loan supply to non-financial corporations is almost unchanged, mainly as a result of the incentives embedded in the ECB's targeted long-term refinancing operations. Our results provide evidence on the interaction between macroprudential and monetary policy, and the positive effects of combining two different sets of incentives to support the resilience of the banking system and credit supply to the real economy.