25 Years IWH

Regulation of International Financial Markets and International Banking

This research group belongs to the IWH Research Cluster Financial Stability and Regulation. The research group analyses causes and consequences of banks' international activities and the regulatory framework they operate in.

Internationally active banks can facilitate an efficient international allocation of capital and provide channels for international risk sharing. But they can also be a source of financial instabilities themselves, thus contributing to international contagion and risk-shifting. This is one reason for the current re-regulation of international banking.

The research group contributes to the literature in three ways. First, the group empirically analyses the channels through which shocks are transmitted by internationally active banks. Second, the group analyses the build-up of aggregate imbalances in integrated banking markets and resulting consequences for the real economy. Third, the group analyses the impact of changes in banking supervision and regulation on (inter)national activities of banks, with a special focus on the European integration process.


IWH Data Project: International Banking Library

Research Cluster
Financial Stability and Regulation

Your contact

Professor Lena Tonzer, PhD
Professor Lena Tonzer, PhD
Mitglied - Department Financial Markets
Send Message +49 345 7753-835 Personal page

Refereed Publications


Too Connected to Fail? Inferring Network Ties from Price Co-movements

Jakob Bosma Michael Koetter Michael Wedow

in: Journal of Business & Economic Statistics , forthcoming


We use extreme value theory methods to infer conventionally unobservable connections between financial institutions from joint extreme movements in credit default swap spreads and equity returns. Estimated pairwise co-crash probabilities identify significant connections among up to 186 financial institutions prior to the crisis of 2007/2008. Financial institutions that were very central prior to the crisis were more likely to be bailed out during the crisis or receive the status of systemically important institutions. This result remains intact also after controlling for indicators of too-big-to-fail concerns, systemic, systematic, and idiosyncratic risks. Both CDS-based and Equity-based connections are significant predictors of bailouts.

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International Banking and Cross-border Effects of Regulation: Lessons from Germany

Jana Ohls Markus Pramor Lena Tonzer

in: International Journal of Central Banking , 2017


We analyze the inward and outward transmission of regulatory changes through German banks’ (international) loan portfolio. Overall, our results provide evidence for international spillovers of prudential instruments. These spillovers are, however, quite heterogeneous between types of banks and can only be observed for some instruments. For instance, domestic affiliates of foreign-owned global banks reduce their loan growth to the German economy in response to a tightening of sector-specific capital buffers, local reserve requirements, and loan-to-value ratios in their home country. Furthermore, from the point of view of foreign countries, tightening reserve requirements is effective in reducing lending inflows from German banks. Finally, we find that business and financial cycles matter for lending decisions.

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Bank Risk Proxies and the Crisis of 2007/09: A Comparison

Felix Noth Lena Tonzer

in: Applied Economics Letters , No. 7, 2017


The global financial crisis has again shown that it is important to understand the emergence and measurement of risks in the banking sector. However, there is no consensus in the literature which risk proxy works best at the level of the individual bank. A commonly used measure in applied work is the Z-score, which might suffer from calculation issues given poor data quality. Motivated by the variety of bank risk proxies, our analysis reveals that nonperforming assets are a well-suited complement to the Z-score in studies of bank risk.

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Complexity and Bank Risk During the Financial Crisis

Thomas Krause Talina Sondershaus Lena Tonzer

in: Economics Letters , 2017


We construct a novel dataset to measure banks’ complexity and relate it to banks’ riskiness. The sample covers stock listed Euro area banks from 2007 to 2014. Bank stability is significantly affected by complexity, whereas the direction of the effect differs across complexity measures.

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Sovereign Credit Risk Co-movements in the Eurozone: Simple Interdependence or Contagion?

Manuel Buchholz Lena Tonzer

in: International Finance , No. 3, 2016


We investigate credit risk co-movements and contagion in the sovereign debt markets of 17 industrialized countries during the period 2008–2012. We use dynamic conditional correlations of sovereign credit default swap spreads to detect contagion. This approach allows us to separate contagion channels from the determinants of simple interdependence. The results show that, first, sovereign credit risk co-moves considerably, particularly among eurozone countries and during the sovereign debt crisis. Second, contagion varies across time and countries. Third, similarities in economic fundamentals, cross-country linkages in banking and common market sentiment constitute the main channels of contagion.

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Working Papers


Delay Determinants of European Banking Union Implementation

Michael Koetter Thomas Krause Lena Tonzer

in: IWH Discussion Papers , No. 24, 2017


To safeguard financial stability and harmonise regulation, the European Commission substantially reformed banking supervision, resolution, and deposit insurance via EU directives. But most countries delay the transposition of these directives. We ask if transposition delays result from strategic considerations of governments conditional on the state of their financial, regulatory, and political systems? Supervisors might try to protect national banking systems and local politicians maybe reluctant to surrender national sovereignty to deal with failed banks. Alternatively, intricate financial regulation might require more implementation time in large and complex financial and political systems. We therefore collect data on the transposition delays of the three Banking Union directives and investigate observed delay variation across member states. Our correlation analyses suggest that existing regulatory and institutional frameworks, rather than banking market structure or political factors, matter for transposition delays.

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Do Conventional Monetary Policy Instruments Matter in Unconventional Times?

Manuel Buchholz Kirsten Schmidt Lena Tonzer

in: IWH Discussion Papers , No. 12, 2017


This paper investigates how declines in the deposit facility rate set by the European Central Bank (ECB) affect bank behavior. The ECB aims to reduce banks’ incentives to hold reserves at the central bank and thus to encourage loan supply. However, given depressed margins in a low interest environment, banks might reallocate their liquidity toward more profitable liquid assets other than traditional loans. Our analysis is based on a sample of euro area banks for the period from 2009 to 2014. Three key findings arise. First, banks reduce their reserve holdings following declines in the deposit facility rate. Second, this effect is heterogeneous across banks depending on their business model. Banks with a more interest-sensitive business model are more responsive to changes in the deposit facility rate. Third, there is evidence of a reallocation of liquidity toward loans but not toward other liquid assets. This result is most pronounced for non-GIIPS countries of the euro area.

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Drivers of systemic risk: Do national and European perspectives differ?

Claudia M. Buch Thomas Krause Lena Tonzer

in: Deutsche Bundesbank Discussion Papers , No. 9, 2017


In Europe, the financial stability mandate generally rests at the national level. But there is an important exception. Since the establishment of the Banking Union in 2014, the European Central Bank (ECB) can impose stricter regulations than the national regulator. The precondition is that the ECB identifies systemic risks which are not adequately addressed by the macroprudential regulator at the national level. In this paper, we ask whether the drivers of systemic risk differ when applying a national versus a European perspective. We use market data for 80 listed euro-area banks to measure each bank’s contribution to systemic risk (SRISK) at the national and the euro-area level. Our research delivers three main findings. First, on average, systemic risk increased during the financial crisis. The difference between systemic risk at the national and the euro-area level is not very large, but there is considerable heterogeneity across countries and banks. Second, an exploration of the drivers of systemic risk shows that a bank’s contribution to systemic risk is positively related to its size and profitability. It decreases in a bank’s share of loans to total assets. Third, the qualitative determinants of systemic risk are similar at the national and euro-area level, whereas the quantitative importance of some determinants differs.

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Inside Asset Purchase Programs: The Effects of Unconventional Policy on Banking Competition

Michael Koetter Natalia Podlich Michael Wedow

in: ECB Working Paper Series , No. 2017, 2017


We test if unconventional monetary policy instruments influence the competitive conduct of banks. Between q2:2010 and q1:2012, the ECB absorbed Euro 218 billion worth of government securities from five EMU countries under the Securities Markets Programme (SMP). Using detailed security holdings data at the bank level, we show that banks exposed to this unexpected (loose) policy shock mildly gained local loan and deposit market shares. Shifts in market shares are driven by banks that increased SMP security holdings during the lifetime of the program and that hold the largest relative SMP portfolio shares. Holding other securities from periphery countries that were not part of the SMP amplifies the positive market share responses. Monopolistic rents approximated by Lerner indices are lower for SMP banks, suggesting a role of the SMP to re-distribute market power differentially, but not necessarily banking profits.

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Uncertainty, Financial Crises, and Subjective Well-being

Lena Tonzer

in: IWH Discussion Papers , No. 2, 2017


This paper focuses on the effect of uncertainty as reflected by financial market variables on subjective well-being. The analysis is based on Eurobarometer surveys, covering 20 countries over the period from 2000 to 2013. Individuals report lower levels of life satisfaction in times of higher uncertainty approximated by stock market volatility. This effect is heterogeneous across respondents: The probability of being unsatisfied is higher for respondents who are older, less educated, and live in one of the GIIPS countries of the euro area. Furthermore, higher uncertainty in combination with a financial crisis increases the probability of reporting low values of life satisfaction.

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