From me to you: Measuring connectedness between Eurozone financial institutions

This paper aims to analyse the tail risk spillover between banks, insurance companies and the shadow banking system in the Eurozone contest. These intra-sectoral interdependencies between financial market participants have contributed to the spread of instability in the financial system. Therefore mapping these links is important for policy-makers to provide supervisory tools and can be a key input into the design of macroprudential policies. For this purpose, we adopt the Tail-Event driven NETwork (TENET) risk model. The TENET is a useful method to map the tail interconnection between the three sectors and to provide systemic risk measures that take into account the “too big to fail” and “too big to interconnected” concepts. The results suggest that each financial sector has a significant impact on the other. By comparing the contribution of each sector, we show that banks are the largest emitters of risk. However, also shadow banking firms are systemic important, given their high level of connection. The work provides a clear view of risk spillovers and interconnection dynamics during the crisis providing a meaningful ranking of the systemic important financial institutions.     

Can banks default overnight? Modelling endogenous contagion on the O/N interbank market

We propose a new model of the liquidity-driven banking system focusing on overnight interbank loans. This significant branch of the interbank market is commonly neglected in the banking system modelling and systemic risk analysis. We construct a model where banks are allowed to use both the interbank and the securities markets to manage their liquidity demand and supply as driven by prudential requirements in a volatile environment. The network of interbank loans is dynamic and simulated every day. We show how the intrasystem cash fluctuations alone, without any external shocks, may lead to systemic defaults, and what may be a symptom of the self-organized criticality of the system. We also analyze the impact of different prudential regulations and market conditions on the interbank market resilience. We confirm that the central bank’s asset purchase programmes, limiting the declines in government bond prices, can successfully stabilize banks’ liquidity demands. The model can be used to analyze the interbank market impact of macroprudential tools.     

Derivatives holdings and systemic risk in the U.S. banking sector

This paper studies the impact of the banks’ portfolio holdings of financial derivatives on the banks’ individual contribution to systemic risk over and above the effect of variables related to size, interconnectedness, substitutability, and other balance sheet information. Using a sample of 95 U.S. bank holding companies from 2002 to 2011, we compare five measures of the banks’ contribution to systemic risk and find that the new measure proposed in this study, Net Shapley Value, outperforms the others. Using this measure we find that banks’ aggregate holdings of five classes of derivatives do not exhibit a significant effect on the bank’s contribution to systemic risk. On the contrary, the banks’ holdings of certain specific types of derivatives such as foreign exchange and credit derivatives increase the banks contributions to systemic risk whereas holdings of interest rate derivatives decrease it. Nevertheless, the proportion of non-performing loans over total loans and the leverage ratio have much stronger impact on systemic risk than derivatives holdings. Therefore, the derivatives’ impact plays a second fiddle in comparison with traditional banking activities related to the former two items.     

Good for one,bad for all: Determinants of individual versus systemic risk

We analyze a sample of large international banks in major advanced economies and examine the impact that bank-specific factors have on an institution's solvency risk and its contribution to systemic risk. We focus on the five categories that the Basel Committee on Banking Supervision has recently proposed as indicators of systemic importance. Our findings suggest that unstable funding is the main factor driving systemic risk. Furthermore, the combination of significant trading activities with global presence appears to exacerbate spillover risks to the global financial system. Interestingly, whereas trading activities contribute to the build-up of correlated or ‘wrong-way’ risk they help to mitigate individual solvency risk. Conversely, a decentralized approach to liquidity management seems to alleviate individual solvency risk but amplifies the transmission of financial distress across the financial system. This suggests that a macro-prudential approach to financial regulation should focus not only on scaling up micro-prudential measures but also on enabling the efficient transfer of risk between financial institutions.     

An integrated macroprudential stress test of bank liquidity and solvency

We propose a new measure of systemic financial distress that incorporates idiosyncratic and systemic risks in the financial system network. Using this measure, we develop an integrated stress test of bank liquidity and solvency risks based on the dynamics of financial distress within the banking system network. We apply this stress test framework to the US banking system and identify systemic vulnerability of individual banks as well as the resilience of the system as a whole to an economic shock. The framework helps us identify and monitor systemic interdependencies between banks. The proposed stress testing framework is useful for practical macroprudential monitoring and is informative for policy making.     

Can We Prove a Bank Guilty of Creating Systemic Risk? A Minority Report

Because increasing a bank's capital requirement to improve the stability of the financial system imposes costs upon the bank, a regulator should ideally be able to prove beyond a reasonable doubt that banks classified as systemically risky really do create systemic risk before subjecting them to this capital punishment. Evaluating the performance of two leading systemic risk models, we show that estimation error alone prevents the reliable identification of the most systemically risky banks. We conclude that it will be a considerable challenge to develop a riskometer that is sound and reliable enough to provide an adequate foundation for macroprudential policy.     

The impact of central bank transparency on systemic risk—Evidence from Central and Eastern Europe

The aim of this paper is to analyze the impact of central bank transparency on systemic risk in emerging banking markets using a sample composed of 34 banks from Central and Eastern Europe for a period spanning from 2005 through 2012. Results indicate a positive and significant relationship between central bank transparency and financial institutions’ contribution to systemic risk. On the other side, increased central bank transparency significantly reduces the idiosyncratic risk of banks. The relationship is influenced by the restrictiveness of regulatory framework. We argue that a more transparent central bank is beneficial for the banking sector from a microprudential perspective. However, it may create incentives for financial institutions to engage in risky activities and through herd behavior may increase individual contribution to the risk of the banking system.     

Measuring systemic importance of financial institutions: An extreme value theory approach

This paper proposes a set of market-based measures on the systemic importance of a financial institution or a group of financial institutions, each designed to capture different aspects of systemic importance of financial institutions. Multivariate extreme value theory approach is used to estimate these measures. Using six big Canadian banks as the proxy for Canadian banking sector, we apply these measures to identify systemically important banks in Canadian banking sector and major risk contributors from international financial institutions to Canadian banking sector. The empirical evidence reveals that (i) the top three banks, RBC Financial Group, TD Bank Financial Group, and Scotiabank, are more systemically important than other banks, while we also find that the size of a financial institution should not be considered as a proxy of systemic importance; (ii) compared to the European and Asian banks, the crashes of the U.S. banks, on average, are the most damaging to Canadian banking sector, while the risk contribution to the Canadian banking sector from Asian banks is quite lower than that from banks in the U.S. and euro area; (iii) the risk contribution to Canadian banking sector exhibits “home bias”, that is, cross-country risk contribution tends to be smaller than domestic risk contribution.     

Hierarchical contagions in the interdependent financial network

We derive the default cascade model and the fire-sale spillover model in a unified interdependent framework. The interactions among banks include not only direct cross-holding, but also indirect dependency by holding mutual assets outside the banking system. Using data extracted from the European Banking Authority, we present the interdependency network composed of 48 banks and 21 asset classes. For the robustness, we employ three methods, called Anan, Hała and Maxe, to reconstruct the asset/liability cross-holding network. Then we combine the external portfolio holdings of each bank to compute the interdependency matrix. The interdependency network is much denser than the direct cross-holding network, showing the complex latent interaction among banks. Finally, we perform macroprudential stress tests for the European banking system, using the adverse scenario in EBA stress test as the initial shock. For different reconstructed networks, we illustrate the hierarchical cascades and show that the failure hierarchies are roughly the same except for a few banks, reflecting the overlapping portfolio holding accounts for the majority of defaults. We also calculate systemic vulnerability and individual vulnerability, which provide important information for supervision and relevant management actions.     

What’s the contingency? A proposal for bank contingent capital triggered by systemic risk

Contingent capital (coco) automatically recapitalizes the banking system during financial crises if the trigger mechanism is properly designed. We propose a dual trigger mechanism based on: (1) aggregate systemic risk in the banking system, measured using CATFIN, and (2) the individual bank’s contribution to overall systemic risk, measured using delta CoVaR. The dual trigger is highly correlated with system-wide insolvency risk and prices systemic risk. We set different triggers for banks, insurance companies and broker-dealers. Using the 99% cut-off, systemic coco issued by Lehman and Bear Stearns would have been triggered in November 2007, months prior to their actual demise.     

基于VaR模型的商业银行体系系统性风险研究

本文以中国2016年之前上市商业银行作为中国银行业的代表,测算银行业系统性 风险VaR。整体来讲,我国银行业系统性风险较低,但VaR在2015年较高。虽如此,我国银行业资本持有量能够抵御银行体系的系统性风险。在系统性风险VaR贡献度方面,本文实证分析表明,在样本期间内,浦发银行、中国银行、农业银行、交通银行贡献度较高。银行体系系统 性风险VaR受GDP增长率和沪深300指数收益率的显著影响。     

Measuring systemic risk-adjusted liquidity (SRL)—A model approach

Little progress has been made so far in addressing—in a comprehensive way—the negative externalities caused by excessive maturity transformation and the implications for effective liquidity regulation of banks. The SRL model combines option pricing theory with market information and balance sheet data to generate probabilistic measure of systemic liquidity risk. It enhances price-based liquidity regulation by linking a bank’s maturity mismatch impacting the stability of its funding with those characteristics of other banks, subject to individual changes in risk profiles and common changes in market conditions impacting funding and market liquidity risk. This approach can then be used (i) to quantify an individual institution’s time-varying contribution to expected losses from system-wide liquidity shortfalls and (ii) to price insurance premia that provide incentives for banks to internalize the social cost of their individual funding decisions.     

Systemic risk in the European sovereign and banking system

We investigate the systemic risk of the European sovereign and banking system during 2008–2013. We utilize a conditional measure of systemic risk that reflects market perceptions and can be intuitively interpreted as an entity’s conditional joint probability of default, given the hypothetical default of other entities. The measure of systemic risk is applicable to high dimensions and not only incorporates individual default risk characteristics but also captures the underlying interdependent relations between sovereigns and banks in a multivariate setting. In empirical applications, our results reveal significant time variation in systemic risk spillover effects for the sovereign and banking system. We find that systemic risk is mainly driven by risk premiums coupled with a steady increase in physical default risk.     

Systemic risk contributions: A credit portfolio approach

We put forward a framework for measuring systemic risk and attributing it to individual banks. Systemic risk is coherently measured as the expected loss to depositors and investors when a systemic event occurs. The risk contributions are calculated so as to ensure a full risk allocation among institutions. Applying our methodology to a panel of 54–86 of the world’s major commercial banks for a 13-year time span with monthly frequency not only allows us to closely match the list of G-SIBs; we can also use individual risk contributions to compute bank-specific surcharges: systemic capital charges as well as countercyclical buffers. We therefore address both dimensions of systemic risk – cross-sectional and time-series – in a single integrated approach. As the analysis of risk drivers confirms, the main focus of macroprudential supervision should be on a solid capital base throughout the financial cycle and de-correlation of banks’ asset values.     

The application of visual analytics to financial stability monitoring

This paper provides an overview of visual analytics—the science of analytical reasoning enhanced by interactive visualizations tightly coupled with data analytics software—and discusses its potential benefits in monitoring systemic financial stability. The core strength of visual analytics is to combine visualization's high-bandwidth information channel to the human analyst with the flexibility and power of rapid-iteration analytics. This combination is especially valuable in the context of macroprudential supervision, which is increasingly dominated by large volumes of dynamic and heterogeneous data. Our contribution is to describe and categorize the analytical challenges faced by macroprudential supervisors, and to indicate where and how visual analytics can increase supervisors’ comprehension of the data stream, helping to transform it into actionable knowledge to support informed decision- and policy-making. The paper concludes with suggestions for a research agenda.     

债券投资如何影响商业银行系统性风险?--基于系统性风险分解的视角

作为我国商业银行最重要的非信贷资产业务,债券投资如何影响银行系统性风险?理论分析表明,债券投资对系统性风险的综合影响取决于其个体风险分散效应和系统关联性提升效应孰强孰弱。在此基础上,本文应用2008-2018年25家上市银行季度数据,实证检验债券投资对系统性风险的影响。结果发现,债券投资同时具有降低银行个体风险和增加银行个体与系统关联性的效果。进一步分析表明,一方面,对于规模较小的商业银行而言,债券投资的个体风险分散效应较弱、系统关联性提升效应较强;另一方面,商业银行持有较多以公允价值计量的债券时,债券投资的系统关联性提升效应较强。本文研究对于监管部门协调微观审慎和宏观审慎监管、防范债券投资业务引致系统性风险具有重要的启示意义。     

A theory of systemic risk and design of prudential bank regulation

Systemic risk is modeled as the endogenously chosen correlation of returns on assets held by banks. The limited liability of banks and the presence of a negative externality of one bank’s failure on the health of other banks give rise to a systemic risk-shifting incentive where all banks undertake correlated investments, thereby increasing economy-wide aggregate risk. Regulatory mechanisms such as bank closure policy and capital adequacy requirements that are commonly based only on a bank’s own risk fail to mitigate aggregate risk-shifting incentives, and can, in fact, accentuate systemic risk. Prudential regulation is shown to operate at a collective level, regulating each bank as a function of both its joint (correlated) risk with other banks as well as its individual (bank-specific) risk.     

Effects of securitization and covered bonds on bank stability

This paper empirically investigates the relationship of securitization and covered bonds with bank stability and highlights that this relationship varies with the level of a bank's involvement in a specific instrument. The study uses the data from 46 securitizing and covered bond issuing listed banks in Europe for 2000–2014. The initial results show that some banks have been heavily involved in securitization activity, while covered bond issuance does not go beyond a certain limit. The results obtained using a quadratic model and a generalized additive model show a U-shaped relationship between securitization and systemic risk of banks. However, some interesting results are obtained for covered bonds. Initial results do not show a significant impact of covered bonds on systemic risk, but further analysis shows the presence of a size effect. The systemic risk of smaller banks increases after the issuance of covered bonds, while larger banks remain unaffected. The study does not support imposing uniform limits on covered bond issuance; rather such limits should be linked to the bank size. However, some regulatory framework is needed to limit banks’ involvement in securitization.     

Banking systemic vulnerabilities: A tail-risk dynamic CIMDO approach

This study proposes a novel framework which combines marginal probabilities of default estimated from a structural credit risk model with the consistent information multivariate density optimization (CIMDO) methodology and the generalized dynamic factor model (GDFM) supplemented by a dynamic t-copula. The framework models banks’ default dependence explicitly and captures the time-varying non-linearities and feedback effects typical of financial markets. It measures banking systemic credit risk in the three forms categorized by the European Central Bank: (1) credit risk common to all banks; (2) credit risk in the banking system conditional on distress on a specific bank or combinations of banks; and (3) the buildup of banking system vulnerabilities over time which may unravel disorderly. In addition, the estimates of the common components of the banking sector short-term and conditional forward default measures contain early warning features, and the identification of their drivers is useful for macroprudential policy. Finally, the framework produces robust out-of-sample forecasts of the banking systemic credit risk measures. This paper advances the agenda of making macroprudential policy operational.     

Systemic risk spillovers in the European banking and sovereign network

We propose a framework for estimating time-varying systemic risk contributions that is applicable to a high-dimensional and interconnected financial system. Tail risk dependencies and systemic risk contributions are estimated using a penalized two-stage fixed-effects quantile approach, which explicitly links time-varying interconnectedness to systemic risk contributions. For the purposes of surveillance and regulation of financial systems, network dependencies in extreme risks are more relevant than simple (mean) correlations. Thus, the framework provides a tool for supervisors, reflecting the market's view of tail dependences and systemic risk contributions. The model is applied to a system of 51 large European banks and 17 sovereigns during the period from 2006 through 2013, utilizing both equity and CDS prices. We provide new evidence on how banking sector fragmentation and sovereign-bank linkages evolved over the European sovereign debt crisis, and how they are reflected in estimated network statistics and systemic risk measures. Finally, our evidence provides an indication that the fragmentation of the European financial system has peaked.