01.07.2015 • 25/2015
Ratingagenturen – Abwärtsspirale durch Herabstufungen unwahrscheinlich
Wissenschaftler des Leibniz-Instituts für Wirtschaftsforschung Halle (IWH) haben die Wechselwirkungen von Länderratings und Zinsen auf Staatsanleihen untersucht und dabei keinerlei empirische Belege für eine Abwärtsspirale gefunden. Vielmehr stellten sie eine langsame Annäherung an ein langfristiges Gleichgewicht aus guten Ratings und niedrigen Zinsen fest. Eine negative Entwicklung wie zum Beispiel die Griechenlands in den Jahren 2010 und 2011 lässt sich nicht aus der Dynamik von Ratings und Zinsen erklären.
Gregor von Schweinitz
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Negative Bonitätsbewertungen und Zinsen auf Staatsanleihen – Gibt es einen Teufelskreis?
Makram El-Shagi, Gregor von Schweinitz
Wirtschaft im Wandel,
Nr. 3,
2015
Abstract
Kann es nach einer Herabstufung der Bonität eines Staates zu einer Dynamik von steigenden Zinsen auf Staatsanleihen und weiter fallenden Ratings kommen, die unausweichlich in einem Staatsbankrott endet? Die hohe Persistenz von Ratings sowie die Beobachtung, dass Zinsen häufig negativ auf eine Herabstufung reagieren, legen die Möglichkeit einer solchen Abwärtsspirale nahe. Empirisch ist diese Dynamik allerdings nicht zu sehen. In den Daten ist im Gegenteil ausschließlich eine sehr langsame Annäherung an ein langfristiges Gleichgewicht von guten Ratings und niedrigen Zinsen zu beobachten. Gleichzeitig ist die Persistenz von Ratings allerdings hoch genug, um nach einer Herabstufung auf ein hochspekulatives Niveau (Rating von B oder schlechter) massive und langandauernde Zinsaufschläge zu erzeugen. Da eine solche Herabstufung in der Realität allerdings äußerst selten erfolgt, ist die Existenz des oben beschriebenen Teufelskreises zu verneinen. Eine negative Entwicklung wie zum Beispiel in Griechenland in den Jahren 2010 und 2011 lässt sich nicht als Ergebnis der Wechselwirkung von Ratings und Zinsen erklären.
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The Joint Dynamics of Sovereign Ratings and Government Bond Yields
Makram El-Shagi, Gregor von Schweinitz
Abstract
In the present paper, we build a bivariate semiparametric dynamic panel model to repro-duce the joint dynamics of sovereign ratings and government bond yields. While the individual equations resemble Pesaran-type cointegration models, we allow for different long-run relationships in both equations, nonlinearities in the level effect of ratings, and asymmetric effects in changes of ratings and yields. We find that the interest rate equation and the rating equation imply significantly different long-run relationships. While the high persistence in both interest rates and ratings might lead to the misconception that they follow a unit root process, the joint analysis reveals that they converge slowly to a joint equilibrium. While this indicates that there is no vicious cycle driving countries into default, the persistence of ratings is high enough that a rating shock can have substantial costs. Generally, the interest rate adjusts rather quickly to the risk premium that is in line with the rating. For most ratings, this risk premium is only marginal. However, it becomes substantial when ratings are downgraded to highly speculative (a rating of B) or lower. Rating shocks that drive the rating below this threshold can increase the interest rate sharply, and for a long time. Yet, simulation studies based on our estimations show that it is highly improbable that rating agencies can be made responsible for the most dramatic spikes in interest rates.
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Risk and Return - Is there an Unholy Cycle of Ratings and Yields?
Makram El-Shagi, Gregor von Schweinitz
Economics Letters,
2015
Abstract
After every major financial crisis, the question about the responsibility of the rating agencies resurfaces. Regarding government bonds, the most frequently voiced concern targeted “unreasonably” bad ratings that might trigger capital flights and increasing risk premia which sanction further rating downgrades. In this paper we develop a multivariate, nonparametric version of the Pesaran type cointegration model that allows for nonlinearities, to show that a unique equilibrium between ratings and sovereign yields exists. Therefore, we have to reject the concern that there is an unholy cycle leading to certain default in the long run.
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Sovereign Credit Risk, Banks' Government Support, and Bank Stock Returns around the World: Discussion of Correa, Lee, Sapriza, and Suarez
Reint E. Gropp
Journal of Money, Credit and Banking,
s1
2014
Abstract
In the years leading up to the 2008–09 financial crisis, many banks around the world greatly expanded their balance sheets to take advantage of cheap and abundantly available funding. Access to international funding markets, in particular, made it possible for banks to reach a size that in some cases was a large multiple of their home countries’ gross domestic product (GDP). In Iceland, for example, assets of the banking system reached up to 900% of GDP in 2007. Similarly, by the end of 2008, assets in UK and Swiss banks exceeded 500% of their countries’ GDPs, respectively. Banks may also have grown rapidly because they may have wanted to reach too-big-to-fail status in their country, implying even lower funding cost (Penas and Unal 2004).
The depth and severity of the 2008–09 financial crisis and the subsequent debt crisis in Europe, however, have cast doubts on the ability of governments to bail out banks when they experience severe difficulties, in particular, in financially fragile environments and faced with large budget imbalances. This has resulted in as what some observers have dubbed a “doom loop”: the combination of weak public finances and weak banks results in a vicious cycle, in which the funding cost of banks increases, as the ability of governments to bail out banks is called into question, in turn increasing the funding cost of these banks and making the likelihood that the government will actually have to step in even higher, which in turn increases funding cost to the government and so forth.
Against this background, the paper by Correa et al. (2014) explores the link between sovereign rating changes and bank stock returns. They show large negative reactions of stock returns in response to sovereign ratings downgrades for banks that are expected to receive government support in case of failure. They find the strongest effects in developed economies, where the credibility of government bail outs is higher ex ante, while the effects are smaller in developing and emerging economies. In my view, the paper makes a number of important contributions to the extant literature.
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The Ex Ante versus Ex Post Effect of Public Guarantees
H. Evren Damar, Reint E. Gropp, Adi Mordel
D. Evanoff, C. Holthausen, G. Kaufman and M. Kremer (eds), The Role of Central Banks in Financial Stability: How has it Changed? World Scientific Studies in International Economics 30,
2013
Abstract
In October 2006, Dominion Bond Rating Service (DBRS) introduced new ratings for banks that account for the potential of government support. The rating changes are not a reflection of any changes in the respective banks’ credit fundamentals. We use this natural experiment to evaluate the consequences of bail out expectations for bank behavior using a difference in differences approach. The results suggest a striking difference between the effects of bail out probabilities during calm times (“ex ante”) versus during crisis times (“ex post”). During calm times, higher bail-out probabilities result in higher risk taking, consistent with the moral hazard view and much of the empirical literature. However, in crisis times, we find that banks with higher bail out probabilities tend to increase their risk taking less compared to banks that were ex ante unlikely to be bailed-out. Charter values are one part of the explanation: Supported banks may have a funding advantage relative to non-supported banks during the crisis. However, we cannot rule out that other factors also may be playing a role, including tighter supervision of supported banks in crisis times.
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Modelling Country Default Risk as a Latent Variable: A Multiple Indicators Multiple Causes Approach
A. Bühn, Stefan Eichler, Dominik Maltritz
Applied Economics,
Nr. 36,
2012
Abstract
We study the determinants of country default risk by applying a Multiple Indicators Multiple Causes (MIMIC) model. This accounts for the fact that country default risk is an unobservable variable. Whereas existing (regression-based) approaches typically use only one of several possible country default risk indicators as the dependent variable, the MIMIC model enables us to consider several indicators at once. The simultaneous consideration of sovereign yield spreads and Standard and Poor (S&P) ratings may help to improve the identification of the latent country default risk. Our results confirm most of the literature's main findings regarding important determinants of country default risk, refute others and provide new evidence to controversial questions.
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The Importance of Estimation Uncertainty in a Multi-Rating Class Loan Portfolio
Henry Dannenberg
IWH Discussion Papers,
Nr. 11,
2011
Abstract
This article seeks to make an assessment of estimation uncertainty in a multi-rating class loan portfolio. Relationships are established between estimation uncertainty and parameters such as probability of default, intra- and inter-rating class correlation, degree of inhomogeneity, number of rating classes used, number of debtors and number of historical periods used for parameter estimations. In addition, by using an exemplary portfolio based on Moody’s ratings, it becomes clear that estimation uncertainty does indeed have an effect on interest rates.
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Competition, Risk-shifting, and Public Bail-out Policies
Reint E. Gropp, H. Hakenes, Isabel Schnabel
Review of Financial Studies,
Nr. 6,
2011
Abstract
This article empirically investigates the competitive effects of government bail-out policies. We construct a measure of bail-out perceptions by using rating information. From there, we construct the market shares of insured competitor banks for any given bank, and analyze the impact of this variable on banks' risk-taking behavior, using a large sample of banks from OECD countries. Our results suggest that government guarantees strongly increase the risk-taking of competitor banks. In contrast, there is no evidence that public guarantees increase the protected banks' risk-taking, except for banks that have outright public ownership. These results have important implications for the effects of the recent wave of bank bail-outs on banks' risk-taking behavior.
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Is Rated Debt Arm's Length? Evidence from Mergers and Acquisitions
Reint E. Gropp, C. Hirsch, Jan Pieter Krahnen
CFS Working Papers, No. 2011/10,
Nr. 10,
2011
Abstract
In this paper we challenge the view that corporate bonds are always arm's length debt. We analyze the effect of bond ratings on the stock price return to acquirers in M&A transactions, which tend to have significant effects on creditor wealth. We find acquirers abnormal returns to be higher if they are unrated, controlling for a wide variety of other effects identified in the literature. Tracing the difference in returns to distinct managerial decisions, we find that, everything else constant, rated firms increase their leverage in takeover transactions by less than their unrated counterparts. Consistent with a significant role for rating agencies, we find monitoring effects to be strongest when acquirer bonds are rated at the borderline between investment grade and junk. Finally, we are able to empirically exclude a large number of alternative explanations for the empirical regularities that we uncover.
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