UNCONVENTIONAL MONETARY POLICY AND SYSTEMIC RISK IN EUROPEAN BANKING
Word count: 14.839
Evi Verhelst Student number : 01202540
Supervisor: Prof. dr. Rudi Vander Vennet Co-supervisor: Elien Meuleman
Master’s Dissertation submitted to obtain the degree of:
Master of Science in Business Engineering
Academic year: 2016 - 2017
UNCONVENTIONAL MONETARY POLICY AND SYSTEMIC RISK IN EUROPEAN BANKING
Word count: 14.839
Evi Verhelst Student number : 01202540
Supervisor: Prof. dr. Rudi Vander Vennet Co-supervisor: Elien Meuleman
Master’s Dissertation submitted to obtain the degree of:
Master of Science in Business Engineering
Academic year: 2016 - 2017
PERMISSION
I declare that the content of this Master’s Dissertation may be consulted and/or reproduced, provided that the source is referenced.
Evi Verhelst
NEDERLANDSTALIGE SAMENVATTING
Toen na de uitbraak van de crisis in 2008 de conventionele maatregelen niet genoeg bleken, introduceerde de Europese Centrale Bank nieuwe, onconventionele maatregelen. Deze waren vooral gericht op het uitbreiden van de bankbalansen. Hoewel deze onconventionele maatregelen er zijn gekomen in de strijd voor de heropleving van het financiële systeem, wordt er in de literatuur toch ook veel bewijs aangereikt dat deze maatregelen bijdragen tot een verhoogd risico. Vandaar doet deze masterproef onderzoek naar het effect van de aankondigingen van deze onconventionele maatregelen op het systeemrisico. Systeemrisico is het risico op een ineenstorting van het financiële systeem als gevolg van de grote complexiteit en de wederzijdse afhankelijkheid tussen banken. In de literatuurstudie worden drie verschillende transmissiekanalen van onconventioneel monetair beleid naar risico en meer bepaald naar het systeemrisico beschreven, namelijk de transmissie door interestvoeten, activaprijzen en liquiditeit. Verder wordt ook de heterogeniteit tussen banken beschreven.
Voor het onderzoek naar het verband tussen het systeemrisico en de maatregelaankondigingen, werd een panelanalyse met 67 beursgenoteerde Europese banken uitgevoerd. De data waartussen de effecten van de aankondigingen werden onderzocht liepen van oktober 2008 tot december 2015 en de hier gebruikte indicator voor het systeemrisico is de ‘Marginal Expected Shortfall’ of kort gezegd de MES. In een eerste stap werden de belangrijkste onconventionele aankondigingen gefilterd, waarop we de effecten van de monetaire beleidsschok gemeten aan de hand van de spread van Italiaanse en Duitse overheidsobligaties op 10 jaar op de MES onderzoeken. Deze regressie werd herhaald voor verschillende bankkarakteristieken om de heterogeniteit tussen banken met veel en weinig kapitaal, banken uit kernlanden en de periferie, banken met een hoog en laag systeemrisico, banken met veel en weinig leningen, niet-uitvoerige leningen, stortingen en niet-interest inkomen te ontdekken. Aangezien deze resultaten weinig zeggend waren werden de regressies nog eens overgedaan, maar dan met andere monetaire schokken. Uit dit onderzoek is gebleken dat het systeemrisico steeg nadat onconventionele programma’s werden aangekondigd. Deze vaststelling bleef ook gelden voor bijna alle programma’s (CBPP, SMP en OMT, QE) afzonderlijk. De enige uitzondering zijn de OMT aankondigingen die, wanneer de SMP aankondigingen buiten beschouwing worden gelaten, het systeemrisico verlagen. Wanneer gekeken wordt naar FRFA en LTRO aankondigen is er geen eenduidig effect waarneembaar.
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ACKNOWLEDGEMENTS
After the choice of the subject for my master’s dissertation in October 2015, the moment of finishing it is finally there. Writing this foreword is the last thing to make this work complete. During these last two years of my master in business engineering, I acquired a lot of new theoretical knowledge where writing this master’s dissertation especially contributed to. To fulfil this big task to good end, I had of course help and support from a lot of different people who I therefore want to thank.
First I want to thank my supervisor Rudi Vander Vennet, who gave me the opportunity to work on a very interesting topic and showed me new captivating insights. Secondly, a heartfelt word of thank is addressed to Elien Meuleman, who was always there to answer my questions, gave good advice, provided me the necessary data and offered support during the whole period. At last, I want to thank my parents, sister and friends for listening when things didn’t go as they should and for the support and believe in me to finish successfully my academic study.
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TABLE OF CONTENTS
NEDERLANDSTALIGE SAMENVATTING ...... i ACKNOWLEDGEMENTS ...... ii LIST OF USED ABBREVIATIONS ...... iv LIST OF TABLES AND FIGURES ...... v 1. INTRODUCTION ...... 1 2. MONETARY POLICY AND SYSTEMIC RISK...... 4 2.1 Unconventional programmes ...... 4 2.2 Transmission channels from monetary policy to systemic risk ...... 5 3. LINK TO BANK HETEROGENEITY ...... 14 3.1 Loans to Total Assets and Non-Performing Loans ...... 14 3.2 Deposits to total liabilities ...... 15 3.3 Capital to total assets ...... 16 3.4 Non-interest income to total income ...... 17 4. METHODOLOGY ...... 18 4.1 Measuring systemic risk ...... 19 4.2 Measuring monetary shock ...... 20 4.3 Model ...... 20 5. DATA ...... 23 6. RESULTS ...... 24 6.1 Results regression analysis ...... 28 6.2 Discussion ...... 33 7. CONCLUSION ...... 36 8. REFERENCES ...... i 9. APPENDIX ...... vi
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LIST OF USED ABBREVIATIONS
ABSPP: Asset-Backed Securities Purchase Programme CAP: Capital to total assets CBPP: Covered Bond Purchase Programme CDS: Credit Default Swap CoVaR: Conditional Value at Risk CSPP: Corporate Sector Purchase Programme DIP: Distress Insurance Premium DIV: Non-interest income to total income DTL: Deposits to total liabilities ECB: European Central Bank EDF: Expected Default Frequency FRFA: Fixed-Rate Full Allotment GovC: Governing Council I-G: Italy-Germany IID: Independently Identically Distributed LTA: Loans to total assets ratio LTRO: Long-Term Refinancing Operations MES: Marginal Expected Shortfall MRO: Main Refinancing Operations NIM: Net Interest Margin NPL: Non-Performing Loans OIS: Overnight Indexed Swap OLS: Ordinary Least Squares OMT: Outright Monetary Transactions PSPP: Public Sector Purchase Programme SMP: Securities Market Programme TLTRO: Targeted Longer-Term Refinancing Operations UMP: Unconventional Monetary Policy QE: Quantitative Easing VaR: Value at Risk
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LIST OF TABLES AND FIGURES
LIST OF TABLES
Table 1: Clarification on Figure 1...... 24 Table 2: Clarification on Figure 2 ...... 26 Table 3: t statistics ...... 35
LIST OF FIGURES
Figure 1: Delta MES in a one day window ...... 24 Figure 2: Delta MES plotted (high versus low capitalised banks)...... 26 APPENDIX: LIST OF TABLES AND FIGURES
LIST OF TABLES
Table A.1: List of announcement days ...... vi Table A.2: List of banks ...... ix Table A.3: Clarification on Figure A.2 ...... x Table A.4: Regression results with spread I-G gov. bond as yield...... x Table A.5: Regression results with different yields ...... xi Table A.6: Regression results with different BM ...... xii Table A.7: Regression results with different yields on particular announcement days ...... xiii Table A.8: Regression results with different yields on particular announcement days, BM: CAP ...... xiv Table A.9: Regression results with different yields on particular announcement days, Core/Per...... xv Table A.10: Regression results with different yields on particular announcement days, (Non-)Syst ... xvi Table A.11: Regression results with different yields on particular announcement days, BM: LTA ..... xvii Table A.12: Regression results with different yields on particular announcement days, BM: NPL .... xviii Table A.13: Regression results with different yields on particular announcement days, BM: DTL ...... xix Table A.14: Regression results with different yields on particular announcement days, BM: DIV ...... xx Table A.15: Regression results with distinction between FRFA and LTRO announcements...... xxi Table A.16: Regression results with distinction between SMP and OMT announcements ...... xxi
LIST OF FIGURES
Figure A.1: Evolution of the yields ...... xxii Figure A.2: Delta MES in a two day window ...... xxiii Figure A.3: Delta OIS 3 months plotted on announcement days ...... xxiii Figure A.4: Delta EURIBOR 3 months plotted on announcement days ...... xxiv Figure A.5: Delta OIS 1 year plotted on announcement days ...... xxiv Figure A.6: Delta EURIBOR 1 year plotted on announcement days ...... xxv Figure A.7: Delta spread EURIBOR-OIS 3 months plotted on announcement days ...... xxv Figure A.8: Delta log (CDS banks 5 year) plotted on announcement days...... xxvi Figure A.9: Delta covered bond yield plotted on announcement days ...... xxvi Figure A.10: Delta spread I-G plotted on announcement days ...... xxvii Figure A.11: Delta log (CDS Italy 5 year) plotted on announcement days ...... xxvii Figure A.12: Delta OIS 10 year plotted on announcement days ...... xxvii Figure A.12: Delta Germany 10 year plotted on announcement days ...... xxviii
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1. INTRODUCTION
The economic meltdown of 2008 has caused a lot of financial problems in the euro area. These called for unprecedented policy responses worldwide, because there was a need to restore stability, maintain liquidity and reduce systemic risk. Systemic risk is an important term that came up during the crisis. This is the risk of collapse of an entire financial system imposed by interdependencies between banks, bank size or bank complexity. The failure of a single entity causes problems of trust which could result in bank runs and finally lead to a cascading failure, which could bring down the whole system. This is what happened to for example Lehman Brothers in 2008. Therefore, the crisis has made it clear that bank regulators have to take into account systemic risk. Since 2008, the European Central Bank (ECB) has set up several measures of unconventional monetary policy. The aim of these measures was to create price stability. However they could have a negative impact on the potential of systemic risk of banks. This is exactly what is going to be examined in this master’s dissertation. This paper will research the impact of different unconventional programmes on the systemic risk potential of 67 European banks. The paper gives an answer to the following important question: “Do unconventional policies significantly, positively or negatively, contribute to systemic risk?” Furthermore, this thesis will determine which of the programmes has had the biggest impact.
This paper will further describe the different transmission channels of the unconventional monetary policies to systemic risk. The effects through interest rates, asset prices and liquidity will be studied. The transmission could be positive, in the sense of decreasing the risk and helping the economy to recover, but it could also be negative, as these measures could also contribute to increasing the potential of systemic risk. Huang, Zhou and Zhu (2010) found in their paper that there is a linear relationship between systemic risk and a bank’s default probability and that bank size is the most important determinant, which is nonlinearly related to systemic risk. The bank’s default probability is one of the factors that can determine the risk perception. Risk-taking became an important concern during the execution of the unconventional measures. Borio and Zhu (2008) especially make notion of a “risk-taking channel”. In the paper, they describe three ways of how this channel could work. In the literature, a lot of reference to this risk-taking channel exist (see, among others, Adrian and Shin, 2009; Gambacorta, 2009; Angeloni, Faia and Lo Duca, 2010; Jimenez, Ongena, Peydro and Saurina, 2014). In the papers of Gambacorta (2009) and Altunbas, Gambacorta and Marques-Ibanez (2014), the link between interest rates and risk-taking is researched. Evidence is found for increased risk- taking in times of low interest rates prior to the crisis. This finding is supported by Jimenez et al. (2014) for Spain and Ioannidou, Ongena and Peydro (2007) for Bolivia. The risk-taking channel
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primarily works through interest rates, but it could also work through other communications of the central banks (Borio and Zhu, 2008). This is linked to the signalling channel. The different links between unconventional monetary policy and risk-taking will be discussed in more detail in section 2.
Whereas a lot of papers focus on how effective the introduced unconventional monetary policies were in easing conditions in the economy and what the responses were in stock markets (Briciu and Lisi, 2015; Rogers, Scotti and Wright, 2014; Swanson, 2015; among many others), this paper contributes to the existing literature on unconventional monetary policy and the risk-taking behaviour of banks. The effect of unconventional policies on systemic risk is analysed, where heterogeneity between banks is included. To analyse the effects of the unconventional policies taken by the ECB on systemic risk, a panel analysis of 67 listed eurozone banks is performed. Our sample contains data from October 2008 until December 2015 and regressions are performed on ECB’s announcement days. Kuttner (2001) and Kohn and Sack (2003) found that announcements of the central bank have an impact on interest rates. Especially for unexpected or unanticipated policy actions (Kuttner, 2001). Following Rosa and Verga (2008), central bank announcements affect asset prices, and again, the impact is the biggest for the unexpected ones. To measure the monetary shock in this paper, we will follow the method suggested by Rogers et al. (2014) in first instance, which defines the monetary policy surprise as using the yield spread between German and Italian 10 year government bonds on the day of an ECB policy announcement. Afterwards, monetary policy shocks on announcement days will be measured with other yields, like the OIS 3 months rate, the OIS 1 year rate, the EURIBOR 3 months rate, the EURIBOR 1 year rate, the covered bond yield, the log CDS 5 year of banks rate, the log CDS 5 year of Italy rate, the OIS 10 year rate and the Germany 10 year government bond rate. The impact on systemic risk is measured by the marginal expected shortfall (MES).
In this master’s dissertation, evidence is found for increased systemic risk due to the introduction of unconventional policies. The policies that are analysed here are Fixed Rate Full Allotment and the Longer Term Refinancing Operations (FRFA and LTRO), the Covered Bond Purchase Programme (CBPP), the Securities Market Programme and the Outright Monetary Transactions (SMP and OMT) and Quantitative Easing (QE). A positive impact of the monetary policy shock on the MES, which is associated with an increase of the MES, was found for the CBPP, SMP and OMT, as well as the QE announcements. An exception of these results are OMT announcement days, when they are observed without SMP announcements. For FRFA and LTRO announcement days, ambiguous effects on systemic risk are found, which is also the case when looking at different bank characteristics in order to identify heterogeneity.
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The remainder of the paper is organized as follows. Section 2 treats the transmission of monetary policy to systemic risk. Section 3 identifies bank heterogeneity. Section 4 outlines the methodology. Section 5 describes the dataset. Section 6 presents the results and section 7 concludes.
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2. MONETARY POLICY AND SYSTEMIC RISK
2.1 Unconventional programmes
At the time when the crisis started and conventional measures turned out to be insufficient, central banks came up with unconventional policies to restore confidence in the interbank markets and government bond markets. The choice of which programme to use, depends on institutional characteristics, the situation of the banking sector and the types of shock hitting (Smaghi, 2009). The essence of the different unconventional policies is to influence expectations in a reliable manner. In this section, the different measures implemented by the ECB will be briefly treated.
The first unconventional programme the ECB unrolled, was the long term refinancing operations. The existence of long term refinancing operations goes back to the foundation of the economic and monetary union, but during the crisis the ECB enormously increased their maturity, up to 36 months. In 2010, after the Greek sovereign debt crisis, the ECB came up with a new facility, the Securities Market Programme (SMP) to put downward pressure on the long term interest rate and to stabilize the euro by buying assets. In July 2012, Mario Draghi (President of the ECB) gave a speech in which he announced that the ECB would do whatever it takes, followed in September 2012, by the introduction of the Outright Monetary Transactions (OMT) programme, which replaced the SMP. There is evidence that both programmes were very successful. Evidence is given by Falagiarda and Reitz (2013), Fratzscher and Rieth (2015), Altavilla, Giannone and Lenza (2014) and Eser and Schwaab (2013). However, Acharya, Eisert, Eufinger and Hirsch (2016a) acknowledge that there is also a negative side of OMT. They found that OMT indirectly recapitalised periphery country banks or banks with a big exposure to the periphery. Therefore some of these banks allowed to renew loans at low interest rates to non-viable companies. This was done in order to avoid realising losses on outstanding loans, but this contains a major risk and banks would not be able to repair their balance sheets. This phenomenon is called evergreening. Next, in September 2014, the targeted long term refinancing operations (TLTRO) took off. This programme encouraged financial institutions to provide more credit to businesses and households, which was done by giving banks the ability to borrow up to 7% of the amount of outstanding loans to the euro area non-financial private sector. Lastly, in January 2015, the ECB launched its expanded asset purchase programme, also known as Quantitative Easing (QE). The QE programme consists of the third covered bond programme (CBPP3), the asset- backed securities purchase programme (ABSPP), the public sector purchase programme (PSPP) and the corporate sector purchase programme (CSPP). Following Rogers et al. (2014) and Wright (2011),
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asset purchases are effective in lowering the prices of the assets being purchased and it tries to lower interest rates that households and firms have to pay in order to boost consumption and investment spending. QE also affects agents’ expectations of monetary policy for the future (Wright, 2011).
2.2 Transmission channels from monetary policy to systemic risk
Systemic risk, the malfunctioning of a financial institution with the accumulation of losses could contribute to the collapse of the whole financial system as a consequence of interdependencies between different institutions. The funding of banks is strongly dependent on the willingness of banks to lend to each other on the interbank market. The danger for systemic risk occurs when the financial sector is undercapitalised, so that they could not and would not help each other out anymore. Following Black, Correa, Huang and Zhou (2013), who investigated which European banks and which bank characteristics were the biggest contributors to systemic risk, the systemic importance of a bank is a joint effect of size, the probability of default and the correlation with other banks. To decrease the risk of financial institutions, new bank regulations were formulated by the Basel-committee. The Basel 1 and 2 rules incorporate provisions for the risk-weighted assets, for the capital requirements and rules regarding providing information. However, as mentioned by Acharya, Pedersen, Philippon and Richardson (2010), these regulations are not enough to get rid of systemic risk. The imposed rules are partly effective in reducing the risk for individual institutions, but not for the whole system. The external costs associated with systemic risk have to be embedded in the internal costs of the institutions, otherwise they will have the tendency to increase their risk-taking (Acharya et al., 2010). Therefore they renewed the regulations, called Basel 3. With these rules, the liquidity of banks will be checked and the quality of capital has to improve (banks have to hold a minimum of TIER 1 capital). In addition, the “too-big-to-fail” banks will be obliged to hold additional capital buffers. “Too-big-to-fail” banks are banks with high importance, because of their size or complexity. When they still fail, they are convinced that governments will help them out. So that kind of banks are not afraid of increasing their risks. Therefore the obligation of additional capital buffers is legitimated. Black et al. (2013) state that banks with more government support have higher incentives to take risks and could increase the systemic risk potential.
As said before, the danger for systemic risk occurs when the financial sector is undercapitalised. During the financial crisis, liquidity dried up and the ECB came up with unconventional measures as described in the paragraph above. In the following part, the different transmission channels of these unconventional monetary policies to systemic risk will be described. This transmission could be
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positive, in the sense of decreasing the risk and helping the economy to recover, but it could also be negative, as these measures could also contribute to increase the potential of systemic risk.
Systemic risk is a consequence of increased risk-taking, which is in turn a consequence of unconventional policies. However, Claeys and Darvas (2015) explain in their paper about the financial stability risks of unconventional measures that increased risk-taking should not always be negative. When risk-taking is less than socially desirable, it can be seen as a good thing. Originally, encouraging the economy to increase risks was an aim of the unconventional monetary policies, however, during the execution of the measures, risk-taking became a concern as it became excessive. The paper of Altunbas et al. (2014) states that the expansionary monetary policy increased bank risk and led to an increased expected default frequency. The risk-taking is also a consequence of asymmetric information and the fact that banks cannot price the risk-taking correctly (De Nicolo, Dell’ Ariccia, Laeven and Valencia, 2010). Now, the effect of the transmission of the monetary policy applied by the ECB, more in particular the introduction of the different unconventional measures, through interest rates, asset prices and liquidity on systemic risk will be studied.
2.2.1 Interest rates
With the start of the crisis in 2008, banks were reluctant to allow new loans to the real economy. As a result, during the crisis, the ECB lowered its key interest rates. In March 2016, the interest rate on the Main Refinancing Operations (MRO) reached the zero percent. At that same time, the interest on deposits was even negative, which means that banks had to pay to deposit their money at the ECB. With these measures, the ECB aims to increase the inflation and strengthen credit supply to the real economy. The effects of the low interest rates are different in the short- and long-term.
In the short-term, credit supply is enhanced, due to the fact that banks are encouraged to set their own lending and deposit rates very low. Because of these low deposit rates, saving will no longer be attractive, but it will encourage lending. Investment spending and consumption of households and firms are supported in this way. This mechanism is also presented as the lending channel in, for instance, the paper of Brissimis and Delis (2010) and Falagiarda and Reitz (2013), whereas evidence for this channel is provided in Boeckx, De Sola Perea and Peersman (2016). Brissimis and Delis (2010) state that the bank lending channel could only exist when there is a decline in the availability of bank loans and that there has to be a change in the reserves of banks. By boosting consumption and investments, low interest rates contribute to an economic recovery due to improved macroeconomic conditions. Altavilla et al. (2014) acknowledge this positive macroeconomic impact of the unconventional measures. These positive macroeconomic effects are also confirmed by Peersman
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(2011) and Claeys and Darvas (2015). However, the level of inflation and economic growth is still on the low side nowadays. Nevertheless, we could say, based on earlier research (Peersman, 2011), that without the introduction of the unconventional measures, the current state of our economy would be much worse. The low interest rates could also lead to positive valuation effects (Lambert and Ueda, 2014).
Due to low interest rates, the liabilities of banks will increase. Banks will increase their short-term funding (Adrian and Liang, 2014) and get more claims from the private sector. This last reason is based on the equality principle, where an asset increase (§2.2.2) will lead to an increase of liabilities (Joyce, Miles, Scott and Vayanos, 2012). This increase in liabilities due to low interest rates, could reduce risk-taking by banks. Declining costs for holding liabilities leads to increased profits. In order to catch these gains, a bank will lower its risky activities (Dell’ Ariccia, Laeven and Marquez, 2013). Another positive effect from low short-term interest rates, in the short run, is the fact that banks could borrow at the short-term interest rate and lend the money out at higher long-term interest rates or invest this money in assets with high returns (Lambert and Ueda, 2014).
In the medium to long-term however, negative effects could dominate. Due to the low interest rates, yields and risk premia will reduce which will result in banks taking on more leverage and they will search for yield by investing money in higher yielding assets (§2.2.2), which increases risk (Lambert and Ueda, 2014). Also the profitability of banks decreases, due to decreasing revenues from long- term loans. Claeys and Darvas (2015) made a distinction between the risk incentives of long- and short-term rates. They state that lower long-term interest rates increase risk-taking, whereas low short-term interest rates and low spreads between long- and short-term interest rates might reduce risk-taking. Adrian and Liang (2014) do not make a distinction between the short-term and longer terms, but they describe the risk-return trade-off as a consequence of monetary easing. Monetary easing reduces risk premia and therefore creates incentives for high returns, which increases risk- taking. This could raise the potential of systemic risk. As mentioned above, due to monetary easing, yields on safe assets decrease, riskier assets therefore become more attractive and both borrowers, investors and banks will take on more risk and get the incentive to search for higher yields. This could be dangerous, because higher asset values lead them to underestimate risk. Another reason for a search for yield is because banks need to match the yield of their assets and liabilities (De Nicolo et al., 2010). Therefore lower interest rates lead also to investments in riskier assets. The statement that effects of low interest rates are positive in the short-term, but negative in the longer term is also acknowledged by Jimenez et al. (2014) and De Nicolo et al. (2010).
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Another effect could be found on the net interest margin. Due to decreasing interest rates, one would expect the net interest margin to decline. The net interest margin is the difference between interest received on loans and interest paid on deposits and borrowings by banks. However, when the short-term interest rate falls, or following Peersman (2011) after a conventional interest rate fall, an increase in the margin could be observed. This is because the interest rate decline is passed on to bank lending rates to a lesser extent than the decline of interest rates that banks receive from the ECB. This increase in the net interest margin will lead to increased risk-taking, due to the bank’s higher equity value and rising balance sheet capacity (Peersman, 2011). However, due to that higher equity value of banks, they will increase monitoring, which decreases risk-taking (e.g. Lambert and Ueda, 2014). In contrast, the net interest margin of banks will start to decline as a consequence of the introduction of some unconventional measures, when these measures approach the long-term interest rates. As a consequence, the profitability of banks will be affected. The net interest margin (NIM) could also be seen as a proxy of the charter value (Schenck, 2014). The charter value is the value that a bank would have if it can keep continuing its business. That value is lost when it goes bankrupt. Therefore the charter value gives an indication about how profitable and stable a bank is (Hendriks and Mosk, n.d.). With regard to the NIM we could say the lower the NIM, the higher the risk-taking, the more chance a bank could go bankrupt, the more chance on a systemic crisis (Schenck, 2014). This is opposite to the intentions of the ECB of lowering interest rates to help recover the economy.
Increasing risk due to low interest rates is also acknowledged by Altunbas, Gambacorta and Marques-Ibanez (2009a,b), who state that when rates are low for a long period, there will be a sharper rise in expected default probabilities, which is consistent with greater risk-taking. This is because banks are granting loans more easily, even when the counterparty has insufficient collateral. However, the ECB states that the risk of borrowers being unable to pay back their loans is bigger when interest rates are high. Therefore when interest rates are high, banks may highly reduce the amount of funds they lend to households and firms. The statement of Altunbas et al. (2009a,b) gets a lot of approval in the literature, as for example from Lambert and Ueda (2014), Wright (2011), Brissismis and Delis (2010), Jimenez et al. (2014), Manganelli and Wolswijk (2007), etc… Black et al. (2013) found CDS spreads originally be relatively low, but they increased dramatically during the sovereign debt crisis. As the CDS spread is a measure for credit risk, the increase in the CDS spread led to increased risk of losses due to a borrower’s failure to repay. Dell’ Ariccia et al. (2013) found that a drop in interest rates leads to lower monitoring, which could also increase credit risk.
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As mentioned before, lower interest rates also lead to an increase in the leverage of banks, due to the lower leverage costs. Adrian and Liang (2014) state that more leverage increases risk-taking and Adrian and Boyarchenko (2013) state that higher leverage is further associated with an increase in financial vulnerability in the form of systemic risk. However, a side remark has to be made, following Claeys and Darvas (2015), leverage has been declined during the last years, due to stricter regulation and supervision. Low interest rates also lead to increasing asset prices (§2.2.2). Due to the fact that investors want to protect themselves against declining yields, they will replace short-term assets with more risky, longer term assets. This leads to increasing asset prices and decreasing term premia (Adrian and Liang, 2014).
Despite the fact that low interest rates help increase the credit supply, low interest rates will also lead people to keep their money instead of depositing it on the bank and as a consequence increase the incentive for banks to keep reserves (Peersman, 2011). This will lead to a lower liquidity, which calls for other measures than solely reduce interest rates (§2.2.3).
2.2.2 Asset prices and risk premia
Unconventional measures led to an expansion of central banks’ balance sheets, due to the introduction of many programmes of asset purchases by the ECB. Asset purchases were found to be the most effective in lowering refinancing costs, compared to exceptional liquidity measures (Szcerbowicz, 2015). Due to the asset purchases of the ECB, the supply of assets of commercial banks will decrease. Following the law of demand and supply, this will lead to increasing prices, which in turn has lower yields as a consequence. This mechanism, in which asset prices increase, lead to higher wealth and is therefore called the wealth-effect channel. This wealth-channel is described for households in Mishkin (2001). Both the positive and negative effects of the unconventional measures on asset prices will be discussed in this paragraph.
In the literature, a lot of possible transmission channels of monetary policy through asset prices are discussed. Most frequently mentioned is the portfolio rebalancing channel. Central banks buy securities from private agents or banks, who get risk-free reserves instead. This decreases the supply for that security, which leads to an increase in asset prices and a reduction in risk premia and consequently also in yields. As a result, better economic conditions are created, due to increasing asset prices and decreasing interest rates. This could contribute to economic recovery. However, due to the reduction in yields, banks will convert cash in higher yielding loans or securities, which are more risky. The portfolio rebalancing channel is discussed by Falagiarda and Reitz (2013), Joyce et al.
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(2012), Szcerbowicz (2015), Fratzscher, Lo Duca, and Straub (2014), Darvas and Claeys (2015), etc., and could only work if the condition of imperfect substitutability is satisfied.
Another popular channel in the literature is the signalling or confidence channel. The confidence channel is described by Fratzscher et al. (2014) and is the most important channel for affecting global markets through the unconventional policies. This channel might affect asset prices by driving expectations of investors through forward guidance of regulators. Another possibility is that the asset purchases of the ECB create incentives for investors to buy assets themselves again, because of the restored trust. They know now that they could sell their assets to the ECB when needed. It gives the signal that assets could be traded whenever wanted. Knowing that central banks will buy assets when necessary make investors reassured and improves market functioning. The SMP and OMT programmes are primarily driven by the effect of the signalling channel.
That asset prices increase due to monetary easing is stated by most of the previously mentioned authors. However, in some papers, there is some doubt about the impact of unconventional measures on stock markets. Haitsma, Unalmis and de Haan (2015) believe in the theory of Hosono and Isobe (2014) and Lambert and Ueda (2014) that before the crisis, monetary easing resulted in increasing stock prices, while during the crisis stock prices decreased. This would be due to the fact that declined interest rates had as a consequence that investors became suspicious about the economic state. On the other hand, Rogers et al. (2014), Wright (2011), Bohl, Siklos and Sondermann (2007) and a lot of other writers, claim the contrary to be true, that monetary easing during the crisis led to increasing stock prices. This last statement is confirmed, against their expectations, by Haitsma et al. (2015) after executing regressions.
The fact that term premia decline is another frequently mentioned consequence of the unconventional policies. These declined term premia led to a reduction in the perceived risk. In the beginning of the crisis, the long-term government bond spreads relative to the Germany long-term bond yield increased in many euro area countries (Falagiarda and Reitz, 2013). Especially in the periphery these increases were the biggest, more specifically mostly in Italy, the country on which Falagiarda and Reitz (2013) focused in their paper. This reflects the distrust of investors who demand a significant risk premium. However, Falagiarda and Reitz (2013) showed in their paper that communications about unconventional measures had a positive outcome on these concerns in financial markets by substantially decreasing the perceived sovereign risk of Italy, particularly the events that occurred during the period 2010-2012. They also found the SMP and OMT programmes to be the most effective in reducing spreads. This statement about the SMP and OMT programmes
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gets approval from respectively Eser and Schwaab (2013) and Altavilla et al. (2014). Eser and Schwaab (2013) found that SMP succeeded in lowering yields when the unconventional measures were introduced and that the programme helped improving market functioning. Altavilla et al. (2014) found that an OMT announcement led to a decrease in the 2-year government bond rates in Italy and Spain. However, German and French bond yields were largely unaffected. Fratzscher and Rieth (2015) also found the OMT programme to be the most effective in reducing risk, more especially in reducing credit risk.
Darvas and Claeys (2015) find that increases in asset prices benefit their holders. However, the danger for bubbles might arise when the increases are excessive. This danger has not yet become reality in the euro zone, but it is important to keep the possibility of bubbles in mind.
2.2.3 Liquidity improvement
As mentioned in the paragraph about the transmission through interest rates, banks decreased their lending activity to the private sector and charged higher loan spreads when the financial crisis unfolded. Therefore a lot of firms, and especially firms with a high dependency on banks affected most by the sovereign debt crisis, namely banks from the periphery (Greece, Ireland, Italy, Portugal and Spain), became financially constrained (Acharya, Eisert, Eufinger and Hirsch, 2016b). The fact that these firms got funding problems was a contributor to the crisis, because some banks caused a credit crunch and because these firms faced decreasing investments and a lower growth (Acharya et al., 2016b). Other European firms were also affected due to spillover effects from the crisis in the periphery countries and the high loan spreads, which is a result of the lending relationships between banks.
An important term is liquidity risk. This is the risk that instruments could not be traded on the moment wanted and was a significant contributor to systemic risk during the financial crisis (Black et al., 2013). Therefore, the ECB started asset purchases to increase the risk-free reserves of banks and to give the signal that assets could be traded whenever wanted. The introduction of the (T)LTROs has also led to an improved liquidity by encouraging banks to allow loans to the real economy. This was needed, because before the introduction of these measures, there was a limited lending to the economy, which contributed to a reinforced recession and financial imbalances (Arghyrou and Kontonikas, 2012). Also due to the measure of the ECB of lowering the interest rates in order to improve economic conditions, people did not deposit their money anymore. This could be seen as a good thing from a macroeconomic perspective, however, few liquidity will be left in the banking
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system. As a consequence, less loans to the economy were allowed. To protect the economy for a new recession or vulnerabilities, governments want a continuation of unconventional measures, but this is in contrast with the goals of central banks. Moreover, the unconventional measures contribute to a lot of heightened risks, as mentioned in earlier paragraphs. Therefore we have to make a trade- off between the risks and advantages (economic recovery) of the unconventional policies.
Because of the improved liquidity, banks could build up higher buffers. This could lead to a decrease in risk-taking, because of protection considerations. It could also lead to a decrease in funding risk, because banks will now more easily obtain the necessary funds. Brunnermeier, Dong and Palia (2012) found that banks who have enough liquidity at their disposal rather tend to engage in traditional banking operations instead of more risky, trading activities. This leads to lower financial losses and therefore less risk. Another merit of improved liquidity is provided by Szcerbowicz (2015). She states that when banks have enough liquidity, banks’ uncertainty will be diminished, counterparty risk premiums decrease and money market tensions will reduce. She also found that in general, improving bank creditworthiness diminishes the chance of a sovereign crisis due to reduced bank bailouts. Moreover, banks with liquidity could restore the financial system themselves by buying sovereign bonds to increase the prices. Large, liquid and well capitalised banks are also more shock resistant, less risky, more profitable and could easily provide loans even when monetary policy is tightening (Altunbas et al., 2014).
Due to the increased quantity of credit, as a consequence of monetary easing, there is an influence on the quality of credit. Adrian and Liang (2014) state that banks with higher levels of capital have lower incentives to reduce the quality of credit. This is confirmed by Brissimis and Delis (2010), who state in their paper that the higher the liquidity, the higher the risk averseness. Because of a sufficient liquidity level, banks do not feel the need to search for yield and want to protect their built up assets. Peersman (2011) also state that through an increase in collateral a higher quality and value of outstanding loans is obtained. However, opposite to the finding of especially Adrian and Liang (2014), due to this increase in collateral, bank’s risk-taking will increase, which results in a greater loan supply (Peersman, 2011). Also Jimenez et al. (2014) state that in times of monetary easing, the lending activity to risky firms increases. This statement is confirmed by Acharya et al. (2016a). They state that after the OMT announcement, more loans were granted to risky firms. Lambert and Ueda (2014) go further and emphasize the principle of evergreening, which was mentioned earlier when the OMT measure was discussed. Evergreening is the phenomenon where banks keep on renewing loans to creditors who actually cannot pay back their loans. This is very risky and when doing this, banks delay their balance sheet repair (Lambert &Ueda, 2014).
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Despite the evidence for increased credit risk, Rogers et al. (2014) declared that central bank purchases are enough to make default unlikely. This is converted into practice through forward guidance by the ECB, which signals that it will buy as much as needed to restore financial stability. In that way, the ECB reduces term and risk premia (§2.2.2) (Rogers et al., 2014).
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3. LINK TO BANK HETEROGENEITY
In the literature, there is a lot of observed heterogeneity at bank level. This especially manifests itself in the response of banks to monetary policy. In this paper, a distinction is made between differences in the amount of bank loans, deposits, capital and the kind of income. This is according to the theory of Brissimis and Delis (2010), who state in their paper that the heterogeneity between banks originates from their different balance sheet characteristics. In particular, they state that banks with more liquidity, capital and market power will be less influenced by changes in monetary policy. They also made claims with regard to risk-taking, among which that banks with higher liquidity or banks which are big in size are more risk averse and that banks with more capital will suffer less from risks, due to higher buffers. In his paper, Ricci (2014) also found evidence for heterogeneity in the impact of monetary policy announcements on stock prices. This was assessed by executing event studies and to achieve more detailed results, regressions were performed. One of the assumptions made in his research is that banks which are perceived as riskier will experience a bigger impact of changes in monetary policy. The ratio between risk-weighted assets and total assets is used by Ricci (2014) to measure the individual risk of banks. A systemic measure is included as well, namely the rating for the country banking system where the institution is located. When the changes in monetary policy are expansive, the assumption is only partially supported. When the monetary policy measures are restrictive, evidence could be found in favour of the assumption.
3.1 Loans to Total Assets and Non-Performing Loans
A first distinction can be made based on the loans to total assets (LTA) ratio and non-performing loans (NPL). Granting loans is dependent on the level of a bank’s risk tolerance. This principle is stated by Paligorova and Santos (2013). They found in their paper that banks with a high risk tolerance undercut the loan spread for more risky firms in times of monetary easing. Therefore, the loan spread between risky and less risky borrowers decreases. Moreover, they state that the longer the easing regime is, the higher the interest rate discount for risky borrowers is. They also found that in times of monetary easing, banks allow bigger loans to riskier borrowers relative to safer ones.
Altunbas et al. (2009a,b) state that banks which are more liquid and well capitalised will grant relatively more loans. These are banks with a low expected default frequency (EDF). Banks with a low EDF could more easily grant loans, due to their high capital buffers, which makes them more resistant to shocks. Banks with a high EDF on the other hand, will be restricted in their lending behaviour. Banks with a high EDF are, for example, smaller banks or banks with higher loan-loss
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provisions. These smaller banks are perceived as more risky, due to their limited capitalisation. When especially looking for evidence after the introduction of the unconventional monetary policies, Acharya et al. (2016b) and Gambacorta and Shin (2016) agree with the statement that well capitalised banks grant more loans. In the paper of Acharya et al. (2016b), they distinguish between weakly and well capitalised banks from the periphery. They state that especially weakly capitalised peripheral banks reduce their lending to the real economy and increase their loan spreads. Considering lower capitalised banks, Boeckx et al. (2016) found evidence for a higher response to credit support measures, on the condition of having a sufficient amount of capital. In general, Mamatzakis and Bermpei (2016) found that banks with a higher LTA ratio have a better performance.
In general, banks with a high LTA ratio will also have more non-performing loans. Following the paper of Acharya et al. (2016a), banks with high levels of capital more easily declare loans non-performing, while lower capitalised banks rather tend to the evergreening of loans. Nevertheless, despite the fact that high capitalised banks more easily declare a loan non-performing, lower capitalised banks will still have a higher stake of NPLs, due to the higher risks they are willing to take by evergreening loans (Klein, 2013). When we look at the LTA ratio, Klein (2013) found that banks with a high LTA ratio are willing to take more risks and that they will have a higher amount of NPLs. This is also confirmed by Gambacorta and Mistrulli (2004). Banks facing a higher level of NPLs will have to deal with a growing uncertainty regarding their capital position, as described by Klein (2013). Therefore, they will have more financing difficulties on the interbank market which will in turn increase their interest rates.
3.2 Deposits to total liabilities
Another way of bank heterogeneity is the distinction between the division of bank liabilities, measured here through the deposits to total liabilities (DTL) ratio. The liquidity measures of the ECB were especially helpful for countries in distress. When the central bank provides liquidity to these countries, the liability side of their balance sheets grows. Ricci (2014) made the assumption that banks with lower liquidity ratios are influenced more, as could be seen from the stock prices, by monetary policy interventions. This assumption is confirmed for an expansionary monetary policy measured by the ratio of customer deposits in total short-term funding.
Demirgüç-Kunt and Huizinga (2010) found that larger banks obtain more non-deposit funding. They also found that banks that rely more on deposit funding face lower funding costs and therefore lower risks, than banks that rely on wholesale capital market. Altunbas et al. (2014) found some similar conclusions. In their paper, they state that banks with lower DTL ratios face higher costs and that
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banks with higher DTL ratios are more stable and contain less risks, due to the existence of deposit insurance. However, Mamatzakis and Bermpei (2016) examine in their paper the relationship between unconventional monetary policy in the US and the performance of banks of different funding structure. They found a negative relationship between unconventional measures and the performance of banks with a high amount of deposits. Demirgüç-Kunt and Huizinga (1999) found in an earlier paper that banks with more deposit funding (than non-deposit funding) are less profitable.
3.3 Capital to total assets
Most of the time, a distinction is made between low- and high capitalised banks. The level of capital can be determined by means of the capital to total assets (CAP) ratio. As mentioned before, Adrian and Liang (2014) state that banks with higher levels of capital have lower incentives to reduce the quality of credit. In turn, banks with low levels of capital will grant more and bigger loans often with fewer collateral to risky firms when the overnight interest rate is low (Jimenez et al., 2014). This incredibly increases their default risk. This statement is partly confirmed by Acharya et al. (2016a). They state that after the OMT announcement, more loans were granted to risky firms. They also find that weakly capitalised firms have high incentives for evergreening loans, which increases risk, whereas highly capitalised banks declare loans from insolvent borrowers non-performing (§4.1). Moreover, capital constrained banks are more exposed to liquidity risk (Pierret, 2015). Capital constrained banks could also start fire sales of assets, which will negatively affect their prices (Szcerbowicz, 2015). Besides, it could be possible that you could not find a buyer to buy these assets in a systemic crisis, because they could not get the funding needed due to the contagion effects of capital restrictions by constrained banks (Pierret, 2015). Brunnermeier et al. (2012) found that banks with a higher amount of leverage are bigger contributors to systemic risk.
However, De Nicolo et al. (2010) claim the contrary. They state that when there are a lot of banks with low capital, a positive relationship between the policy rate and bank risk taking can be found, which implies that risk-taking will be reduced thanks to the presence of low capitalised banks in times of monetary easing. Acharya et al. (2016b) agree with this finding. They distinguish between banks from the core and banks from the periphery. They found weakly capitalised periphery country banks to take less risks regarding granting loans with respect to the higher capitalised periphery country banks (§3.1). Ricci (2014) assumes that higher capitalised banks experience a lower impact of monetary policy interventions than lower capitalised banks. This assumption is partially supported, but only for an expansionary monetary policy measured with the TIER 1 ratio.
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3.4 Non-interest income to total income
Brissimis and Delis (2010) found that profitability of banks is dependent on a change in the interest rates. Banks could take deposits available at short term at lower rates and use these borrowings to invest in high-yield investments or lend it out at higher rates. This also contains a risk. Moreover, banks with a high profitability are very reassured and could relax lending standards. By easily giving away loans, they increase their credit risk, which could in turn also decrease the profitability. In the paper of Ricci (2014), event studies were performed, which indicate that abnormal returns of stocks seem to be higher for more profitable banks, as well as for banks with a higher ratio between cost and income.
When really looking at the non-interest income to total income (DIV) ratio, mixed results are found. Brunnermeier et al. (2012) found that banks with a higher DIV ratio are bigger contributors to systemic risk. They also decomposed the non-interest income in two components and the effects of both of the components can be found in their paper. In the past, the volume of these non-interest income of banks was still bigger than it is nowadays, thanks to the regulations that were set up since the crisis started. However, the paper of Saunders, Schmid and Walter (2016) showed that banks with higher non-interest income have a higher profitability and no evidence is found that banks with a higher DIV ratio increased bank risk exposure nor that they would contribute more to systemic risk. They even found that a high DIV ratio lowered failure probabilities when looking at individual banks. De Jonghe, Diepstraten and Schepens (2015) found that the effect of the DIV ratio on systemic risk is dependent on the size of the bank. Stiroh (2004) found no clear and unambiguous relation between the DIV ratio and profitability and risk of banks.
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4. METHODOLOGY
In the literature, a lot of evidence was given for obtaining lower risk after the introduction of the unconventional measures, however, there is also found a lot of theoretical and empirical evidence that the unconventional measures contributed to increased risk. Therefore, in this master’s dissertation, the extent to which the unconventional programmes had and have an influence on the systemic risk of European banks will be determined.
When the ECB announces an intervention of unconventional monetary policy, it is very likely that there are changes in bond and stock market returns. To determine if the unconventional programmes had an influence on these bond and stock markets, it is necessary that the announcement is unexpected. Otherwise the information regarding the programme would already be priced in. Measuring the effects of unexpected announcements (monetary policy surprise) is done in very different ways by different authors. Some use survey data, others newspaper articles, but mostly used are asset prices (Haitsma et al., 2015; among many others). In this master’s dissertation, I will make use of the method of Rogers et al. (2014), which defines the monetary policy surprise by using the yield spread between Italian and German 10 year government bonds at the day of an ECB policy announcement. The methodology that will be applied is the event study approach. The surprise (the event) will be investigated in different windows around the announcement date. The choice of the window size must be considered carefully, because when the window is too wide, other shocks might play a role and when it is too small, the effect of the news might not yet got through. Due to the fact that the spread between Italian and German 10 year government bonds will especially capture SMP and OMT announcements, other yields (money market rates, CDS rates, government bond rates,…) will also be used to capture the effects of (particular) unconventional measures on systemic risk.
To explore the influence of the unconventional programmes on systemic risk, we also need data on a systemic risk indicator, in this case the marginal expected shortfall (MES) of European banks. Because of the absence of intraday data, daily data will be used. As defined by Acharya et al. (2010), the MES is “the average of return of each bank during the 5% worst days for the market”. They found in their paper that the MES and leverage predict each bank’s contribution to a crisis. In a last step, it is investigated if the impact of the unconventional programmes is substantial and which of the programmes had the biggest impact (positive or negative) on systemic risk, with heterogeneity between banks taken into account. Therefore the sign and the magnitude of different
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unconventional policies at announcement dates will be analysed. These policies will be outlined further. 4.1 Measuring systemic risk
As mentioned above, to capture and measure systemic risk, the marginal expected shortfall (MES) will be used. There are a lot of other measures for risk however, such as value at risk (VaR), but the expected loss or volatility are found to have almost no explanatory power for specific events, as described in Acharya et al. (2010). Therefore it is decided to use the MES here. The VaR measure is used to measure risk of an individual institution in isolation (Adrian and Brunnermeier, 2011). Therefore it is not suited to measure systemic risk, which needs to capture the risk of the whole system and not only the risk of one institution in isolation. To overcome this problem, Adrian and Brunnermeier (2011) propose a new method: the CoVaR. However, this measure still has the disadvantage that it only measures the system’s loss conditional on the individual institutions, so it can only identify systemically important institutions and cannot appropriately aggregate the systemic risk contributions of individual institutions (Adrian and Brunnermeier, 2011). Another disadvantage of this risk measure is that CoVaR treat firms that have the same correlation with the market, but that have different volatilities in the same manner (Acharya, Engle and Richardson, 2012). The MES however does take this limitation of the CoVaR into account. Other important measures of risk are the distress insurance premium (DIP) (Black et al., 2013) and SRISK (Acharya et al., 2012). An advantage of these two indicators is that they take the size of a financial institution explicitly into account, whereas neither MES nor CoVaR do this (Black et al., 2013). A concern of SRISK is that it computes only partly the systemic risk of a firm, namely it computes only the expected capital shortfall. Following Huang, Zhou and Zhu (2010), the MES and DIP measures are very similar. The difference is in the fact that the MES is calculated based on equity returns, while the DIP is based on CDS data. CDS data capture the default risk, whereas equity returns are important for having information about the market capitalisation. It could be concluded that each measure has its advantages and disadvantages. The paper of Idier, Lamé and Mésonnier (2013) investigated how useful the MES is as a systemic risk indicator. They found that the MES is not that good of an indicator for predicting the risk before a crisis. Nevertheless, in this paper, the MES is used for measuring the risk of past events. Moreover, given the fact that the MES is an objective distribution- based statistical measure (Black et al., 2013) and that it is, together with the leverage, effective in predicting each bank’s contribution to a crisis (Acharya et al., 2010), this research will capture systemic risk by making use of the MES.
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4.2 Measuring monetary shock
In first instance, the monetary shock will be measured by using a sovereign bond spread. Therefore I will make use of the method of Rogers et al. (2014), which defines the monetary policy surprise by using the yield spread between Italian and German 10 year government bonds at the day of an ECB policy announcement. This approach is different from measuring a monetary shock in the United States or Japan. This is due to the fact that the circumstances were different in the euro zone. In the euro zone, the intra-euro area spreads are very important in the transmission mechanism of monetary policy (Rogers et al., 2014). People would reach wrong conclusions when only German yields would be measured. This is because actions that succeeded in lowering sovereign spreads tended to drive German yields up (Rogers et al., 2014). Therefore the unconventional measures would wrongly seem to be part of a contractionary policy. Despite this finding, other yields will be included in the analysis to measure the impact of particular unconventional programmes on systemic risk. However, it will be kept in mind that yields could go up instead of go down when actions for lowering sovereign spreads are undertaken.
4.3 Model
In a first step, an event study is performed in which the difference in the MES (ΔMES) in a one day window is plotted on announcement days. This is done for 67 European banks (§9. Appendix: Table A.2) as the mean of the cross-sections. This visual representation will also be showed for banks with high versus low capital and for a two day window.
In a next step, different regressions are performed. Again, the panel of the 67 European banks is used with daily figures (5 days/week) due to the absence of intradaily data. To interpret the regression results correctly, the delta yield is multiplied by minus one and due to the really small obtained coefficients, delta MES is also multiplied by 100, so that more clearness can be created about the differences and the magnitude of the coefficients. The parameters are estimated by the ordinary least squares (OLS) method with a fixed effects estimator. To adjust for heteroscedasticity, all of the regressions are performed with a robust standard error, namely white cross-section. To execute the first type of regression, the following formula is used,
Δ , = + β∗ Δ spread I − G + ∗ dummy +δ ∗ Δ spread I − G ∗ dummy + ε , , ε , ~ iid (0, ) (1)
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in which delta spread I-G is the difference of the spread between Italian and German 10 year government bonds on two subsequent days and the dummy has a value of one at announcement days and zero for other days. Announcement days are days on which statements about the monetary
2 policy are made. Lastly, the assumption is made that ε ~ iid (0,σε ). This assumes that observations are serially uncorrelated and that they are homoscedastic (Verbeek, 2004). Due to the fact that we want to perform an event study, the previous regression formula is fixed on announcement days. Therefore we set the dummy at one and the formula becomes simpler,