Dominik Menno
- 16 February 2026
- WORKING PAPER SERIES - No. 3188Details
- Abstract
- Under which conditions do usability constraints for regulatory capital buffers emerge? To answer this question, we build a non-linear structural banking sector model with a minimum capital requirement that banks are not allowed to breach, and a capital buffer requirement (CBR) that banks can breach but if they do so potential stigma applies. We prove that even very low stigma costs induce large buffer usability constraints, i.e. when faced with losses banks will deleverage significantly to avoid that their capital ratio falls below the CBR. Our findings imply that non-releasble regulatory capital buffers are unlikely to fully achieve their macro stabilisation goal to support aggregate loan supply when the banking system faces losses.
- JEL Code
- D21 : Microeconomics→Production and Organizations→Firm Behavior: Theory
E44 : Macroeconomics and Monetary Economics→Money and Interest Rates→Financial Markets and the Macroeconomy
E51 : Macroeconomics and Monetary Economics→Monetary Policy, Central Banking, and the Supply of Money and Credit→Money Supply, Credit, Money Multipliers
G21 : Financial Economics→Financial Institutions and Services→Banks, Depository Institutions, Micro Finance Institutions, Mortgages
G28 : Financial Economics→Financial Institutions and Services→Government Policy and Regulation
- 13 July 2023
- WORKING PAPER SERIES - No. 2828Details
- Abstract
- Based on a non-linear equilibrium model of the banking sector with an occasionally-binding equity issuance constraint, we show that the economic impact of changes in bank capital requirements depends on the state of the macro-financial environment. In ”normal” states where banks do not face problems to retain enough profits to satisfy higher capital requirements, the impact on bank loan supply works through a ”pricing channel” which is small: around 0.1% less loans for a 1pp increase in capital requirements. In ”bad” states where banks are not able to come up with sufficient equity to satisfy capital requirements, the impact on loan supply works through a ”quantity channel”, which acts like a financial accelerator and can be very large: up to 10% more loans for a capital requirement release of 1pp. Compared to existing DSGE models with a banking sector, which usually feature a constant lending response of around 1%, our state-dependent impact is an order of magnitude lower in ”normal” states and an order of magnitude higher in ”bad” states. Our results provide a theoretical justification for building up a positive countercyclical capital buffer in ”normal” macro-financial environments.
- JEL Code
- D21 : Microeconomics→Production and Organizations→Firm Behavior: Theory
E44 : Macroeconomics and Monetary Economics→Money and Interest Rates→Financial Markets and the Macroeconomy
E51 : Macroeconomics and Monetary Economics→Monetary Policy, Central Banking, and the Supply of Money and Credit→Money Supply, Credit, Money Multipliers
G21 : Financial Economics→Financial Institutions and Services→Banks, Depository Institutions, Micro Finance Institutions, Mortgages
G28 : Financial Economics→Financial Institutions and Services→Government Policy and Regulation