Please address media inquiries to:
phone: +49 345 7753-720
e-mail: presse@iwh-halle.de
Team Public Relations
Germany’s economy is so bad even sausage factories are closingIWHThe Economist, January 15, 2026
This paper analyzes the effects of bank capital regulation on the link between bank size and volatility. Using bank-level data for 27 advanced economies over the 2000–2014 period, we estimate a power law that relates the volume of a bank’s loan portfolio to the volatility of loan growth. Our analysis reveals, first, that more stringent capital regulation weakens the size-volatility nexus. Hence, in countries with more stringent capital regulation, large banks show, ceteris paribus, lower loan portfolio volatility. Second, the effect of tighter capital requirements on the size-volatility nexus becomes stronger for the upper tail of the bank size distribution. This is in line with capitalization decreasing with bank size, such that larger banks tend to be more affected by increasing capital requirements. Third, in countries with higher sectoral capital buffers, the size-volatility nexus is weaker.
This paper provides evidence for the propagation of idiosyncratic mortgage supply shocks to the macroeconomy. Based on micro-level data from the Home Mortgage Disclosure Act for the 1990-2016 period, our results suggest that lender-specific mortgage supply shocks affect aggregate mortgage, house price, and employment dynamics at the regional level. The larger the idiosyncratic shocks to newly issued mortgages, the stronger are mortgage, house price, and employment growth. While shocks at the level of shadow banks significantly affect mortgage and house price dynamics, too, they do not matter much for employment.
To finance resolution funds, the regulatory toolkit has been expanded in many countries by bank levies. In addition, these levies are often designed to reduce incentives for banks to rely excessively on wholesale funding resulting in high leverage ratios. At the same time, corporate income taxation biases banks’ capital structure towards debt financing in light of the deductibility of interest on debt. A recent paper published in the Journal of Banking and Finance shows that the implementation of bank levies can significantly reduce leverage ratios, however, only in case corporate income taxes are not too high. The result demonstrates that the effectiveness of regulatory tools can depend upon non-regulatory measures such as corporate taxes, which differ at the country level.
Regulatory bank levies set incentives for banks to reduce leverage. At the same time, corporate income taxation makes funding through debt more attractive. In this paper, we explore how regulatory levies affect bank capital structure, depending on corporate income taxation. Based on bank balance sheet data from 2006 to 2014 for a panel of EU-banks, our analysis yields three main results: The introduction of bank levies leads to lower leverage as liabilities become more expensive. This effect is weaker the more elevated corporate income taxes are. In countries charging very high corporate income taxes, the incentives of bank levies to reduce leverage turn insignificant. Thus, bank levies can counteract the debt bias of taxation only partially.
Regulatory bank levies set incentives for banks to reduce leverage. At the same time, corporate income taxation makes funding through debt more attractive. In this paper, we explore how regulatory levies affect bank capital structure, depending on corporate income taxation. Based on bank balance sheet data from 2006 to 2014 for a panel of EU-banks, our analysis yields three main results: The introduction of bank levies leads to lower leverage as liabilities become more expensive. This effect is weaker the more elevated corporate income taxes are. In countries charging very high corporate income taxes, the incentives of bank levies to reduce leverage turn ineffective. Thus, bank levies can counteract the debt bias of taxation only partially.
This paper investigates the link between mortgage supply shocks at the banklevel and regional house price growth in the U.S. using micro-level data on mortgage markets from the Home Mortgage Disclosure Act for the 1990-2014 period. Our results suggest that bank-specific mortgage supply shocks indeed affect house price growth at the regional level. The larger the idiosyncratic shocks to newly issued mortgages, the stronger is house price growth. We show that the positive link between idiosyncratic mortgage shocks and regional house price growth is very robust and economically meaningful, however not very persistent since it fades out after two years.
We explore the impact of large banks and of financial openness for aggregate growth. Large banks matter because of granular effects: if markets are very concentrated in terms of the size distribution of banks, idiosyncratic shocks at the bank-level do not cancel out in the aggregate but can affect macroeconomic outcomes. Financial openness may affect GDP growth in and of itself, and it may also influence concentration in banking and thus the impact of bank-specific shocks for the aggregate economy. To test these relationships, we use different measures of de jure and de facto financial openness in a linked micro-macro panel dataset. Our research has three main findings: First, bank-level shocks significantly impact on GDP. Second, financial openness lowers GDP growth. Third, granular effects tend to be stronger in financially closed economies.
Does the mere presence of big banks affect macroeconomic outcomes? In this paper, we develop a theory of granularity (Gabaix, 2011) for the banking sector, introducing Bertrand competition and heterogeneous banks charging variable markups. Using this framework, we show conditions under which idiosyncratic shocks to bank lending can generate aggregate fluctuations in the credit supply when the banking sector is highly concentrated. We empirically assess the relevance of these granular effects in banking using a linked micro-macro dataset of more than 80 countries for the years 1995-2009. The banking sector for many countries is indeed granular, as the right tail of the bank size distribution follows a power law. We then demonstrate granular effects in the banking sector on macroeconomic outcomes. The presence of big banks measured by high market concentration is associated with a positive and significant relationship between bank-level credit growth and aggregate growth of credit or gross domestic product.
