Taxes, risk taking, and financial stability

After the global financial crisis, the use of taxes to enhance financial stability received new attention. This paper analyzes the corrective role of taxes in banking and compares two instruments, namely, an allowance for corporate equity (ACE), which mitigates the debt bias in corporate taxation, and a Pigovian tax on bank debt (bank levy). We emphasize financial stability gains driven by lower bank asset risk and develop a principal‐agent model, in which risk taking depends on the bank's capital structure and, by extension, on the tax treatment of debt and equity. We find that (i) the ACE unambiguously reduces risk taking, (ii) bank levies reduce risk taking if they are independent of bank performance but may be counterproductive otherwise, and (iii) taxes are especially effective if regulatory capital requirements are constrained to low levels.