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Germany’s economy is so bad even sausage factories are closingIWHThe Economist, January 15, 2026
Relying on confidential supervisory data related to the 2016 EU-wide stress test, this paper presents novel empirical evidence that supervisory scrutiny associated to stress testing has a disciplining effect on bank risk. We find that banks that participated in the 2016 EU-wide stress test subsequently reduced their credit risk relative to banks that were not part of this exercise. Relying on new metrics for supervisory scrutiny that measure the quantity, potential impact, and duration of interactions between banks and supervisors during the stress test, we find that the disciplining effect is stronger for banks subject to more intrusive supervisory scrutiny during the exercise. We also find that a strong risk management culture is a prerequisite for the supervisory scrutiny to be effective. Finally, we show that a similar disciplining effect is not exerted neither by higher capital charges nor by more transparency and related market discipline induced by the stress test.
Bank regulators interfere with the efficient allocation of resources for the sake of financial stability. Based on this trade-off, I compare how different capital requirements affect default probabilities and the allocation of market shares across heterogeneous banks. In the model, banks‘ productivity determines their optimal strategy in oligopolistic markets. Higher productivity gives banks higher profit margins that lower their default risk. Hence, capital requirements indirectly aiming at high-productivity banks are less effective. They also bear a distortionary cost: Because incumbents increase interest rates, new entrants with low productivity are attracted and thus average productivity in the banking market decreases.
We test whether limited market discipline imposes exit barriers and poor profitability in banking. We exploit an exogenous shock to the governance of government-owned banks: the unification of counties. County mergers lead to enforced government-owned bank mergers. We compare forced to voluntary bank exits and show that the former cause better bank profitability and efficiency at the expense of riskier financial profiles. Regarding real effects, firms exposed to forced bank mergers borrow more at lower cost, increase investment, and exhibit higher employment. Thus, reduced exit frictions in banking seem to unleash the economic potential of both banks and firms.
I develop a theoretical model to investigate the effect of simultaneous regulation with a leverage ratio and a risk-weighted ratio on banks‘ risk taking and banking market structure. I extend a portfolio choice model by adding heterogeneity in productivity among banks. Regulators face a trade-off between the efficient allocation of resources and financial stability. In an oligopolistic market, risk-weighted requirements incentivise banks with high productivity to lend to low-risk firms. When a leverage ratio is introduced, these banks lose market shares to less productive competitors and react with risk-shifting into high-risk loans. While average productivity in the low-risk market falls, market shares in the high-risk market are dispersed across new entrants with high as well as low productivity.
We use mortgage loan application data of the Home Mortgage Disclosure Act (HMDA) to shed light on the role of banks’ market power on their presumably insufficient risk screening activities in the U.S. mortgage market in the pre-crisis era. We find that banks with higher market power protect their charter value. The effect is stronger for banks that have more information about local markets.
Finding the proper balance between state and market is challenging. Especially in banking (Stiglitz, 1993). Banks in their function as financial intermediaries are risky and inherently prone to failure (Diamond and Dybvig, 1983; Diamond, 1984). But they provide services of vital importance to the economy in the form of payment services, credit supply for investments, inter-temporal liquidity transformation, or management of savings accounts. Consequently, the stability of the banking and financial sector is of public interest. In the least, the financial crisis was an unpleasant reminder to the industrialized world about the severe repercussions of unstable banking systems.
