La thèse analyse la question de la stabilité du système financier international dans son ensemble et plus précisément comment améliorer sa résilience. Chaque chapitre se focalise sur un type d'acteur dans ce système complexe, à savoir les banques, les organismes de supervision et les régulateurs internationaux. Le premier chapitre introduit de nouvelles techniques d'optimisation pour accélérer le calcul de mesure de risque dans les banques et les institutions financières. Il propose également une étude théorique pour valider les algorithmes d'optimisation proposés. Le second vise à quantifier l'externalité négative générée par les activités d'une banque ou d'une d'institution financière. Finalement, le dernier chapitre concerne la coopération entre régulateurs nationaux en présence de coûts de coordination en proposant une analyse qui s'appuie sur la théorie des jeux. / We first investigate the computational complexity for estimating quantile based risk measures, such as the widespread Value at Risk for banks and Solvency II capital requirements for insurance companies, via nested Monte Carlo simulations. The estimator is a conditional expectation type estimate where two stage simulations are required to evaluate the risk measure: an outer simulation is used to generate risk factor scenarios that govern price movements and an inner simulation is used to evaluate the future portfolio value based on each of those scenarios. The second essay considers the financial stability from a macro perspective. Measuring negative externalities of banks is a major challenge for financial regulators. We propose a new risk management approach to enhance the financial stability and to increase the fairness of financial transactions. The basic idea is that a bank should assume as much risk as it creates. Any imbalance in the tails of the distribution of profit and losses is a sign of the bank's failure to internalize its externalities or the social costs associated with its activities. The aim of the third essay is to find a theoretical justification toward the mutual benefits for members of a bonking union in the context of a strategic interaction model. We use a unique contagion dynamic that marries the rich literature of game theory, contagion in pandemic crisis and the study of collaboration between regulators. The model is focused toward regulating asset classes, not individual banks. This special design addresses moral hazard issues that could result from government intervention in the case of crisis.

Cette thèse examine les déterminants de la présence des banques à l’étranger et de leur mode d’implantation (succursales ou filiales) ainsi que les effets de leurs stratégies d’internationalisation sur leurs performances et sur le risque systémique. Elle est composée de trois essais empiriques sur l’internationalisation des banques européennes. Le chapitre 1 étudie si le niveau de développement des pays d’accueil et la maturité de leur système financier conditionnent l’impact de la réglementation bancaire sur les choix de localisation et de mode d’implantation à l’étranger, sous une forme exclusive de succursales ou de filiales ou selon un modèle mixte associant les deux formes. Les résultats indiquent sur la période 2011–2013 que les banques européennes choisissent d’être présentes plutôt dans les pays à hauts revenus qui ont des conditions strictes d’entrée et d'activités mais une supervision plus souple où elles s’implantent davantage sous forme de filiales. En revanche, elles privilégient les pays à revenus intermédiaires dont les autorités de supervision sont strictes mais ne restreignent pas les activités bancaires. Elles préfèrent également une présence avec des succursales dans les pays à bas revenus dont la réglementation est rigoureuse. Enfin, bien qu’une réglementation du capital plus sévère dissuade l’internationalisation des banques, toute implantation à l’étranger se fait néanmoins sous forme de succursales. Le chapitre 2 analyse comment la complexité organisationnelle et géographique des banques à l’étranger affecte le risque bancaire et la rentabilité de la banque-mère. Les résultats montrent que les banques présentes dans plus de pays prennent moins de risque, ont une plus faible probabilité de défaut, un plus faible risque de levier ainsi qu’une rentabilité plus faible. Il apparait également que les banques les plus complexes qui opèrent à la fois sous forme de filiales et de succursales dans plusieurs régions du monde sont, à l’exception du risque de l’actif, en moyenne moins risquées que celles qui s’installent uniquement sous forme de succursales. Le chapitre 3 considère la solidité de l’ensemble du système bancaire et teste si la présence des banques à l'étranger par le biais de filiales affecte le risque systémique différemment en temps normal (2005–2007), en temps de crise financière et de crise de la dette souveraine européenne (2008–2011) et au cours des années suivantes (2012–2013). L’analyse montre que la détention de filiales étrangères est associée en temps normal à un moindre risque systémique mais que lorsque le système bancaire fait face à des chocs sévères, l’effet est négatif, persistant et s’accroit durant les années d’après crises. Ces résultats suggèrent que l'internationalisation des banques contribue habituellement à une plus grande stabilité financière mais qu’elle amplifie l’impact systémique des crises. / This thesis examines the determinants of foreign banks’ presence and their organizational strategies abroad and tests how such internationalization affects bank performance and systemic risk. The dissertation is comprises of three empirical essays on European banks. The first chapter analyzes whether differences in economic development of the host countries and the maturity of their financial system are relevant to explain how banking regulation affects the choice of the foreign location and the organizational strategy of an exclusive organizational network with only branches or subsidiaries or a mix model with both affiliates’ types. The findings indicate that over the 2011–2013 period, European banks prefer high-income countries with numerous activity restrictions and weaker supervision but less developed countries with less restrictions and stronger supervision. Regarding the choice of foreign organizational form, banks rather operate subsidiaries in high and middle-income countries with stringent entry requirements but prefer branches in developing countries with stringent capital requirements and greater supervisory power. However, banks always tend to avoid locations with stronger capital regulation than at home. Yet when they are present in such countries, they operate branches. The second chapter investigates how foreign organizational and geographic complexity affect the parent bank’s individual risk and profitability. Our results show that being present abroad is beneficial for bank stability as it contributes to lower default risk. Banks present abroad through both subsidiaries and branches appear to be more stable than banks present under one form only. Being present with branches only is the most effective way to reduce risk-taking. Nevertheless, higher geographic dispersion of affiliates around different world regions is associated with higher volatility of earnings and higher profitability. Chapter 3 considers the state and soundness of the banking system and examines whether the presence of banks abroad with subsidiaries affects bank systemic risk differently during calm period (2005–2007), distress times of the global financial crisis and the European Sovereign debt crisis (2008–2011), and years after (2012–2013). We show for European listed banks that operating subsidiaries abroad is associated with lower systemic risk in normal times. However, when the banking system is facing severe shocks, such internationalization produces on systemic risk reversed and negative effects that are long-lived and aggravated in the years after the crises. Our findings suggest that bank internationalization and foreign complexity are important for greater stability in normal times but turn out to increase instability during years of financial turmoil and in the aftermath.

O objetivo principal deste artigo é estimar a contribuição dos bancos no mercado financeiro brasileiro ao risco sistêmico utilizando a metodologia proposta por Adrian e Brunnermeier (2011). Esta aplicação é relevante do ponto de vista de avaliação da regulação vigente, e na verificação dos padrões de risco vigentes mercado nacional. Entre os resultados encontrados, destacam-se três pontos distintos: (a) há uma grande divergência nos patamares de risco entre os períodos de baixa e alta estabilidade monetária; (b) a relação entre tamanho e risco gerado pelas instituições financeiras é não linear; e (c) assim como visto em trabalhos aplicados a outros países, o Value at Risk nem sempre acompanha a contribuição de um banco ao risco sistêmico, colocando em xeque as métricas da regulação vigente. / The main goal this of this paper is estimate the systemic risk contribution of the banks in the Brazilian financial markets, using the CoVaR methodology proposal in Adrian and Brunnermeier (2011). This application is relevant from the point of view of the effective regulation, and the examination of the patterns of the national market risk. Among the obtained results, stand out are three distinctive points: (a) there is a huge difference in levels of risk between poor and high stability environments; (b) the relationship between size and risk generated by financial institutions is not linear; and (c) as seen in previous works applied in others countries, the Value at Risk does not always follow the bank risk contribution to systemic risk, jeopardizing the metrics of the effective regulation.

Neste trabalho, aprofundamos o estudo sobre risco sistêmico via funções de agregação. Consideramos três carteiras diferentes como proxy para um sistema econômico, estas carteiras são consistidas por duas funções de agregação, baseadas em todos as ações do E.U.A, e um índice de mercado. As medidas de risco aplicadas são Value at Risk (VaR), Expected Shortfall (ES) and Expectile Value at Risk (EVaR), elas são previstas através do modelo GARCH clássico unido com nove funções de distribuição de probabilidade diferentes e mais por um método não paramétrico. As previsões são avaliadas por funções de perda e backtests de violação. Os resultados indicam que nossa abordagem pode gerar uma função de agregação adequada para processar o risco de um sistema previamente selecionado. / In this work, we deepen the study of systemic risk measurement via aggregation functions. We consider three different portfolios as a proxy for an economic system, these portfolios are consisted in two aggregation functions, based on all U.S. stocks and a market index. The risk measures applied are Value at Risk (VaR), Expected Shortfall (ES) and Expectile Value at Risk (EVaR), they are forecasted via the classical GARCH model along with nine distribution probability functions and also by a nonparametric approach. The forecasts are evaluated by loss functions and violation backtests. Results indicate that our approach can generate an adequate aggregation function to process the risk of a system previously selected.

O objetivo principal deste artigo é estimar a contribuição dos bancos no mercado financeiro brasileiro ao risco sistêmico utilizando a metodologia proposta por Adrian e Brunnermeier (2011). Esta aplicação é relevante do ponto de vista de avaliação da regulação vigente, e na verificação dos padrões de risco vigentes mercado nacional. Entre os resultados encontrados, destacam-se três pontos distintos: (a) há uma grande divergência nos patamares de risco entre os períodos de baixa e alta estabilidade monetária; (b) a relação entre tamanho e risco gerado pelas instituições financeiras é não linear; e (c) assim como visto em trabalhos aplicados a outros países, o Value at Risk nem sempre acompanha a contribuição de um banco ao risco sistêmico, colocando em xeque as métricas da regulação vigente. / The main goal this of this paper is estimate the systemic risk contribution of the banks in the Brazilian financial markets, using the CoVaR methodology proposal in Adrian and Brunnermeier (2011). This application is relevant from the point of view of the effective regulation, and the examination of the patterns of the national market risk. Among the obtained results, stand out are three distinctive points: (a) there is a huge difference in levels of risk between poor and high stability environments; (b) the relationship between size and risk generated by financial institutions is not linear; and (c) as seen in previous works applied in others countries, the Value at Risk does not always follow the bank risk contribution to systemic risk, jeopardizing the metrics of the effective regulation.

This dissertation provides a complex study of systemic financial risk and its quantification. In the first part, the paper summarizes the main assumptions and tools of macroprudential policy, which became an important regulatory policy after the financial crisis of 2007-2009. The main parts of the paper deal with the construction of indicators of financial systemic risk and stress, where the paper distinguishes the quantitative expression of the contemporaneous financial stress from the continually developing systemic risk. The paper analyzes several methods of financial stress index construction, whose main task is to identify the contemporaneous rate of risk in different sectors of financial system using market prices of assets. The outcome of the paper is the identification and historical description of periods of heightened financial stress and the recognition of a regional character of the periods of stress. Apart from the index of the contemporaneous stress of financial system, the paper brings a systemic risk indicator, which captures the development of systemic risk in time, and which is a suitable leading indicator for the identification of periods of financial stress. The systemic risk indicator has identified, with a lead of two to three years, the increasing risk of the banking sectors of the countries in the region before the onset of the financial crisis of 2007-2009. In the conclusion, the paper points out the suitability of both indicators for the calculation of the amount of countercyclical capital buffer used in the new Basel III measures.

This thesis deals with stress testing of the banking sector. Stress tests are a set of analytical tools used to test the resilience and financial stability of the banking sector. At the beginning of the work financial stability and systemic risk impact not only in the form of sys-temically important financial institutions are discussed. Followed by a chapter on stress tests, which describes historic development of stress testing approaches to testing of individual banking risks and their implementation in the form of stress testing. Stress testing methodo-logy is described primarily from the perspective of the Czech National Bank, the importance of banking regulation and supervision in Basel III is also presented. In the final chapter of the thesis there are commented results of Czech National Bank's stress tests, and EU wide stress tests 2014, launched in cooperation with European Banking Authority, European Central Bank and the European Systemic Risk Board.

My dissertation topic is on the impact of changes in the monetary policy interest rate target on bank distress and systemic risk in the U.S. banking system. The financial crisis of 2007-2009 had devastating effects on the banking system worldwide. The feeble performance of financial institutions during the crisis heightened the necessity of understanding systemic risk exhibited the critical role of monitoring the banking system, and strongly necessitated quantification of the risks to which banks are exposed, for incorporation in policy formulation. In the aftermath of the crisis, US bank regulators focused on overhauling the then existing regulatory framework in order to provide comprehensive capital buffers against bank losses. In this context, the Basel Committee proposed in 2011, the Basel III framework in order to strengthen the regulatory capital structure as a buffer against bank losses. The reform under Basel III framework aimed at raising the quality and the quantity of regulatory capital base and enhancing the risk coverage of the capital structure. Separately, US bank regulators adopted the Dodd-Frank Wall Street Reform and Consumer Protection Act (2010) to implement stress tests on systemically important bank holding companies (SIBs). Concerns about system-wide distress have broadened the debate on banking regulation towards a macro prudential approach. In this context, limiting bank risk and systemic risk has become a prolific research field at the crossroads of banking, macroeconomics, econometrics, and network theory over the last decade (Kuritzkes et al., 2005; Goodhart and Sergoviano, 2008; Geluk et al., 2009; Acharya et al., 2010, 2017; Tarashev et al., 2010; Huang et al., 2012; Browless and Engle, 2012, 2017 and Cummins, 2014). The European Central Bank (ECB) (2010) defines systemic risk as a risk of financial instability “so widespread that it impairs the functioning of a financial system to the point where economic growth and welfare suffer materially.” While US bank regulators and policy-makers have moved to strengthen the regulatory framework in the post-crisis period in order to prevent another financial crisis, a growing recent line of research has suggested that there is a significant link between monetary policy and bank distress (Bernanke, Gertler and Gilchrist, 1999; Borio and Zhu, 2008; Gertler and Kiyotaki, 2010; Delis and Kouretas, 2010; Gertler and Karadi, 2011; Delis et al., 2017). In my research, I examine the link between the monetary policy and bank distress. In the first chapter, I investigate the impact of the federal funds rate (FFR) changes on the banking system distress between 2001 and 2013 within an unrestricted vector auto-regression model. The Fed used FFR as a primary policy tool before the financial crisis of 2007-2009, but focused on quantitative easing (QE) during the crisis and post-crisis periods when the FFR hit the zero bound. I use the Taylor rule rate (TRR, 1993) as an “implied policy rate”, instead of the FFR, to account for the impact of QE on the economy. The base model of distress includes three macroeconomic indicators—real GDP growth, inflation, and TRR—and a systemic risk indicator (Expected capital shortfall (ES)). I consider two model extensions; (i) I include a measure of bank lending standards to account for the changes in the systemic risk due to credit tightening, (ii) I replace inflation with house price growth rate to see if the results remain robust. Three main results can be drawn. First, the impulse response functions (IRFs) show that raising the monetary policy rate contributed to insolvency problems for the U.S. banks, with a one percentage point increase in the rate raising the banking systemic stress by 1.6 and 0.8 percentage points, respectively, in the base and extend models. Second, variance decomposition (VDs) analysis shows that up to ten percent of error variation in systemic risk indicator can be attributed to innovations in the policy rate in the extended model. Third, my results supplement the view that policy rate hikes led to housing bubble burst and contributed to the financial crisis of 2007-2009. This is an example for how monetary policy-making gets more complex and must be conducted with utmost caution if there is a bubble in the economy. In the second chapter, I examine the prevalence and asymmetry of the effects on bank distress from positive and negative shocks to the target fed fund rate (FFR) in the period leading to the financial crisis (2001-2008). A panel model with three blocks of control variables is used. The blocks include: positive/negative FFR shocks, macroeconomic drivers, and bank balance sheet indicators. A distress indicator similar to Texas Ratio is used to proxy distress. Shocks to FFR are defined along the lines suggested by Morgan (1993). Three main results are obtained. First, FFR shocks, either positive or negative, raise bank distress over the following year. Second, the magnitudes of the effects from positive and negative shocks are unequal (asymmetric); a 100 bps positive (negative) shock raises the bank distress indicator (scaled from 0 to 1) by 9 bps (3 bps) over the next year. Put differently, after a 100 bps positive (negative) shock, the probability of bankruptcy rises from 10% to 19% (13%). Third, expanding operations into non-banking activities by FHCs does not benefit them in terms of distress due to unanticipated changes in the FFR as FFR shocks (positive or negative) create similar levels of distress for BHCs and FHCs. In the third chapter, I explore the systemic risk contributions of U.S. bank holding companies (BHCs) from 2001 to 2015 by using the expected shortfall approach. Developed by analogy with the component expected shortfall concept, I decompose the aggregate systemic risk, as measured by expected shortfall, into several subgroups of banks by using publicly available balance sheet data to define the probability of bank default. The risk measure, thus, encompasses the entire universe of banks. I find that concentration of assets in a smaller number of larger banks raises systemic risk. The systemic risk contribution of banks designated as SIFIs increased sharply during the financial crisis and reached 74% at the end of 2015. Two-thirds of this risk contribution is attributed to the four largest banks in the U.S.: Bank of America, JP Morgan Chase, Citigroup and Wells Fargo. I also find that diversifying business operations by expanding into nontraditional operations does not reduce the systemic risk contribution of financial holding companies (FHCs). In general, FHCs are individually riskier than BHCs despite their more diversified basket of products; FHCs contribute a disproportionate amount to systemic risk given their size, all else being equal. I believe monetary policy-making in the last decade carries many lessons for policy makers. Particularly, the link between the monetary policy target rate and bank distress and systemic risk is an interesting topic by all accounts due to its implications and challenges (explained in more detail in first and second chapters). The literature studying the relation between bank distress and monetary policy is fairly small but developing fast. The models I investigate in my work are simple in many ways but they may serve as a basis for more sophisticated models. / Economics

This dissertation presents a liquidity stress-testing model for evaluating liquidity and systemic risk in banks from developed and emerging economies respectively. The model further relies on simulations to generate liquidity buffer losses for both a non-crisis and crisis period as well. The emerging economy is represented by South Africa (SA) and the developed economy by the United Kingdom (henceforth UK). The Liquidity Stress Tester model (LST) has been successfully applied to both the Dutch and UK markets in previous research. The model's flexibility and adaptability allows it to assess different banking systems and different reactions (buffer restoration and leverage targeting) of participants within these milieus. The LST considers feedback effects arising from bank reactions and allows for the assessment of severely stressed haircuts and systemic risk increases caused by reputation degradation and increased contagion from other banks. Losses stemming from the second round effects of a liquidity event are explored through the reactions conducted by banks in the banking system. The study conducts a review of liquidity risk models utilised in previous research. Characteristics of these models and the data they used are highlighted, shedding light on the advantages and shortcomings of these models. Possible restrictions in liquidity risk management are also explored. The study discusses the relevance of the South African/UK economies' comparison, as well as the selected periods chosen for investigation. To assist further research with the LST, the study illustrates and discusses how it is modelled and developed in Microsoft Office Excel. The results obtained illustrate the potential severity of second round feedback effects of a liquidity event on liquidity positions in banks. The effects of mitigating actions conducted by banking institutions reacting to initial liquidity stress shocks are explored, as well as the way these actions could potentially affect second round effects on banks. The analysis and discussion of simulated results attempts to isolate and identify characteristics of economies and periods used that may have contributed to specific liquidity events. The study concludes with a summary of the research and suggestions for possible future work and development using the LST. / MCom (Risk Management), North-West University, Potchefstroom Campus, 2013

This dissertation presents a liquidity stress-testing model for evaluating liquidity and systemic risk in banks from developed and emerging economies respectively. The model further relies on simulations to generate liquidity buffer losses for both a non-crisis and crisis period as well. The emerging economy is represented by South Africa (SA) and the developed economy by the United Kingdom (henceforth UK). The Liquidity Stress Tester model (LST) has been successfully applied to both the Dutch and UK markets in previous research. The model's flexibility and adaptability allows it to assess different banking systems and different reactions (buffer restoration and leverage targeting) of participants within these milieus. The LST considers feedback effects arising from bank reactions and allows for the assessment of severely stressed haircuts and systemic risk increases caused by reputation degradation and increased contagion from other banks. Losses stemming from the second round effects of a liquidity event are explored through the reactions conducted by banks in the banking system. The study conducts a review of liquidity risk models utilised in previous research. Characteristics of these models and the data they used are highlighted, shedding light on the advantages and shortcomings of these models. Possible restrictions in liquidity risk management are also explored. The study discusses the relevance of the South African/UK economies' comparison, as well as the selected periods chosen for investigation. To assist further research with the LST, the study illustrates and discusses how it is modelled and developed in Microsoft Office Excel. The results obtained illustrate the potential severity of second round feedback effects of a liquidity event on liquidity positions in banks. The effects of mitigating actions conducted by banking institutions reacting to initial liquidity stress shocks are explored, as well as the way these actions could potentially affect second round effects on banks. The analysis and discussion of simulated results attempts to isolate and identify characteristics of economies and periods used that may have contributed to specific liquidity events. The study concludes with a summary of the research and suggestions for possible future work and development using the LST. / MCom (Risk Management), North-West University, Potchefstroom Campus, 2013