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.     

What is the systemic risk exposure of financial institutions?

I compare the performance of three measures of institution-level systemic risk exposure — Exposure CoVaR (Adrian and Brunnermeier, 2016), systemic expected shortfall (Acharya et al., 2016), and Granger causality (Billio et al., 2012). I modify Exposure CoVaR to allow for forecasting, and estimate the ability of each measure to forecast the performance of financial institutions during systemic crisis periods in 1998 (LTCM) and 2008 (Lehman Brothers). I find that Exposure CoVaR forecasts the within-crisis performance of financial institutions, and provides useful forecasts of future systemic risk exposures. Systemic expected shortfall and Granger causality do not forecast the performance of financial institutions reliably during crises. I also find, using cross-sectional regressions, that foreign equity exposure and securitization income determine systemic risk exposure during the 1998 and 2008 crises, respectively; financial institution size determines systemic risk exposure during both crisis periods; and executive compensation does not determine systemic risk exposure.     

Systemic risk in the Chinese financial system: A panel Granger causality analysis

In this paper, we investigate China’s changing financial interconnectedness via the presence of Granger-causality between firm level factors (Leverage, Market To Book Value and Returns) and systemic risk measures ($\Delta$CoVaR, MES, and SRISK ). The analysis is based on 161 Chinese financial intermediaries (14 Traditional Banks, 16 Finance Services, 131 Real Estate Finance Developers) continuously listed over the period 2007:1–2021:1. We find that, in addition to traditional banks, finance companies and real estate finance developers pose systemic threats to the Chinese financial system, in particular during the Global Financial Crisis and the 2015 Chinese stock crash. Finally, the outbreak of COVID-19 pandemic has put under strain the Chinese financial system, in particular the finance services.     

Does financial connectedness predict crises?

The global financial crisis has reignited interest in models of crisis prediction. It has also raised the question whether financial interconnectedness—a possible source of systemic risk—can serve as an early warning indicator of crises. In this paper, we examine the ability of connectedness in the global network of financial linkages to predict systemic banking crises during the 1978–2010 period. Our results indicate that increases in a country’s own connectedness and decreases in its neighbours’ connectedness are associated with a higher probability of banking crises after controlling for macroeconomic fundamentals. Our findings suggest that financial interconnectedness has early warning potential, especially for the 2007–2010 wave of systemic banking crises.     

Has the financial system become safer after the crisis? The changing nature of financial institution risk

Six years after the collapse of Lehman Brothers, the question of whether the U.S. financial system has become less risky remains unanswered. On the one side, new regulations including Dodd-Frank and Basel III have made improvements by requiring higher bank capital, and financial institutions themselves have reduced risk-taking activities. On the other side, it has been argued that “the fundamental risks remained and the efforts of regulators and politicians were simply rearranging the deckchairs on the Titanic.” (Baily and Elliott, 2013) This paper highlights the changing nature of financial institution risk from 2005 to 2011. It finds that while these institutions have become less risky individually after the crisis, the financial market has become more vulnerable to systemic contagion. The causal inference that the crisis and the post-crisis legislation have gradually changed the nature of financial institution risk is drawn from a quasi-experimental design. This finding suggests that the ever more integrated financial system might experience more synchronized contractions in future crises, providing empirical support for the proposals of the inter-bank collective regulation of banks by Acharya (2009) in addition to the intra-bank collective regulations as in Froot and Stein (1998) and BIS (1996, 1999).     

Comparing early warning systems for banking crises

Despite the extensive literature on prediction of banking crises by Early Warning Systems (EWSs), their practical use by policy makers is limited, even in the international financial institutions. This is a paradox since the changing nature of banking risks as more economies liberalise and develop their financial systems, as well as ongoing innovation, makes the use of EWS for informing policies aimed at preventing crises more necessary than ever. In this context, we assess the logit and signal extraction EWS for banking crises on a comprehensive common dataset. We suggest that logit is the most appropriate approach for global EWS and signal extraction for country-specific EWS. Furthermore, it is important to consider the policy maker's objectives when designing predictive models and setting related thresholds since there is a sharp trade-off between correctly calling crises and false alarms.     

Econometric measures of connectedness and systemic risk in the finance and insurance sectors

We propose several econometric measures of connectedness based on principal-components analysis and Granger-causality networks, and apply them to the monthly returns of hedge funds, banks, broker/dealers, and insurance companies. We find that all four sectors have become highly interrelated over the past decade, likely increasing the level of systemic risk in the finance and insurance industries through a complex and time-varying network of relationships. These measures can also identify and quantify financial crisis periods, and seem to contain predictive power in out-of-sample tests. Our results show an asymmetry in the degree of connectedness among the four sectors, with banks playing a much more important role in transmitting shocks than other financial institutions.     

Systemic risk in an interconnected banking system with endogenous asset markets

We analyze the emergence of systemic risk in a network model of interconnected bank balance sheets. The model incorporates multiple sources of systemic risk, including size of financial institutions, direct exposure from interbank lendings, and asset fire sales. We suggest a new macroprudential risk management approach building on a system wide value at risk (SVaR). Under the SVaR metric, the contribution of individual banks to systemic risk is well defined and can be approximated by a Shapley value-type measure. We show that, in a SVaR regime, a fair systemic risk charge which is proportional to a bank's individual contribution to systemic risk diverges from the optimal macroprudential capitalization of the banks from a planner's perspective. The results have implications for the design of macroprudential capital surcharges.     

金融衍生工具与银行系统性风险

从巴林银行倒闭到中航油、中石化衍生品交易巨亏,重新审视金融衍生工具与系统性风险的关系成为必然。金融衍生工具运用规模和比例呈急剧上升趋势,其初衷为对冲风险,契合金融服务实体经济功能,但由于其交易规则具有复杂性和不透明性,实施效果亟待检验。本文采用金融衍生工具视角,探索了分类金融衍生工具对银行系统性风险的影响及作用机理。结果表明,金融衍生工具会加剧银行系统性风险,包括外汇类和利率类金融衍生工具。金融衍生工具运用总体效果并不理想,且存在情境依赖,作用发挥呈现异质性。在后金融危机时代以及股市处于熊市时,金融衍生工具均加剧了银行系统性风险,在危机前则降低了银行系统性风险,但当处于牛市时则无显著影响。此外,在市场化进程高、机构持股比例高时,金融衍生工具加剧银行系统性风险的作用更为明显。本文从一个新的视角检验了银行系统性风险的影响因素,为探究其成因提供了新解释,也为未来系统性风险防控提供了新思路。     

Systemic risk and asymmetric responses in the financial industry

To date, an operational measure of systemic risk capturing nonlinear tail-comovements between system-wide and individual bank returns has not yet been developed. This paper proposes an extension of the CoVaR methodology in Adrian and Brunnermeier (2011) to capture the asymmetric response of the banking system to positive and negative shocks to the market-valued balance sheets of individual banks. Building on a comprehensive sample of U.S. banks in the period 1990–2010, the evidence in this paper shows that ignoring asymmetries that feature tail-interdependences may lead to a severe underestimation of systemic risk. On average, the relative impact on the system of a fall in individual market value is sevenfold that of an increase. Moreover, the downward bias in systemic-risk measuring from ignoring this asymmetric pattern increases with bank size. In particular, the conditional tail-comovement between the banking system and a bank that is losing market value belonging to the top size-sorted decile is nearly 5.5 times larger than the unconditional tail-comovement versus 3.3 times for banks in the bottom decile. The asymmetric model also produces much better fitting, with the restriction that gives rise to the standard symmetric model being rejected for most firms in the sample, particularly, in the segment of large-scale banks. This result is important from a regulatory and supervisory perspective, since the asymmetric generalization enhances the capacity to monitor systemic interdependences.     

Leverage-induced systemic risk under Basle II and other credit risk policies

We use a simple agent based model of value investors in financial markets to test three credit regulation policies. The first is the unregulated case, which only imposes limits on maximum leverage. The second is Basle II and the third is a hypothetical alternative in which banks perfectly hedge all of their leverage-induced risk with options. When compared to the unregulated case both Basle II and the perfect hedge policy reduce the risk of default when leverage is low but increase it when leverage is high. This is because both regulation policies increase the amount of synchronized buying and selling needed to achieve deleveraging, which can destabilize the market. None of these policies are optimal for everyone: risk neutral investors prefer the unregulated case with low maximum leverage, banks prefer the perfect hedge policy, and fund managers prefer the unregulated case with high maximum leverage. No one prefers Basle II.     

A comprehensive approach to measuring the relation between systemic risk exposure and sovereign debt

Using an integrated model to control for simultaneity, as well as new risk measurement techniques such as Adapted Exposure CoVaR and Marginal Expected Shortfall (MES), we show that the aggregate systemic risk exposure of financial institutions is positively related to sovereign debt yields in European countries in an episodic manner, varying positively with the intensity of the financial crisis facing a particular nation. We find evidence of a simultaneous relation between systemic risk exposure and sovereign debt yields. This suggests that models of sovereign debt yields should also include the systemic risk of a country's financial system in order to avoid potentially important mis-specification errors. We find evidence that systemic risk of a country's financial institutions and the risk of sovereign governments are inter-related and shocks to these domestic linkages are stronger and longer lasting than international risk spillovers. Thus, the channel in which domestic sovereign debt yields can be affected by another nation's sovereign debt is mostly an indirect one in that shocks to a foreign country's government finances are transmitted to that country's financial system which, in turn, can spill over to the domestic financial system and, ultimately, have a destabilizing effect on the domestic sovereign debt market.     

Systemic risk and the refinancing ratchet effect

The combination of rising home prices, declining interest rates, and near-frictionless refinancing opportunities can create unintentional synchronization of homeowner leverage, leading to a “ratchet” effect on leverage because homes are indivisible and owner-occupants cannot raise equity to reduce leverage when home prices fall. Our simulation of the U.S. housing market yields potential losses of $1.7 trillion from June 2006 to December 2008 with cash-out refinancing vs. only $330 billion in the absence of cash-out refinancing. The refinancing ratchet effect is a new type of systemic risk in the financial system and does not rely on any dysfunctional behaviors.     

Systemic risk measures and regulatory challenges

This paper discusses different definitions of systemic risk and identifies the challenges, which regulators face in addressing this phenomenon. We conducted a systematic literature review of 4859 abstracts to categorize the various methodologies developed to measure systemic risk. In total, 60 systemic risk measures proposed post-2000 have been critically appraised to inform academics and regulators of their practical applications and model vulnerabilities. This review suggests that most of these methods focus on individual financial institutions rather than on system stability. Those methodologies directly reflect the current regulations, which aim to ensure individual institutions’ soundness. As macro-prudential regulation evolves, policy-makers face the issues of understanding contagion and how regulations should be implemented. This paper also discusses new systemic risk and regulatory challenges resulting from the current COVID-19 pandemic.     

Systemic risk of insurers around the globe

We study the exposure and contribution of 253 international life and non-life insurers to systemic risk between 2000 and 2012. For our full sample period, we find systemic risk in the international insurance sector to be small. In contrast, the contribution of insurers to the fragility of the financial system peaked during the recent financial crisis. In our panel regressions, we find the interconnectedness of large insurers with the insurance sector to be a significant driver of the insurers’ exposure to systemic risk. In contrast, the contribution of insurers to systemic risk appears to be primarily driven by the insurers’ leverage.     

Fragility,stress, and market returns

We propose a novel risk measure that relates to subsequent negative conditional stock market returns. Our risk measure considers both the fragility and stress of the market. Fragility is measured by the Fragility Index developed by Berger and Pukthuanthong (2012) and market stress is based on several economic variables. Results show that incorporating both market stress and fragility improves the information content of a risk measure. Our risk measure relates to poor subsequent monthly market returns. We show the risk measure contains predictive information in a purely ex-ante specification.     

Interbank contagion and resolution procedures: inspecting the mechanism

This paper develops a network model of a stylized banking system in which banks are connected to one another through interbank claims, which allows us to study the diffusion of default avalanches triggered by an exogenous shock under a number of different assumptions on the degree of interconnectedness, level of capitalization, liquidity buffers, the size of the interbank market and fire-sales. We expand upon the existing literature by comparing two alternative resolution mechanisms: (i) liquidations triggered by either illiquidity or insolvency-related distress implying asset sales and compensation of creditors; and (ii) a bail-in mechanism avoiding bank closure by forcing a recapitalization provided by bank creditors. Our model speaks to how contagion dynamics unravel via illiquidity-driven defaults in the first case and higher-order losses in the latter one. Within this framework, we show how the liquidity risk externality can be resolved, and we put forward a macro-criterion to assess the adequacy of the liquidity ratio introduced with Basel III.     

The stability–concentration relationship in the Brazilian banking system

In this article, the relation between non-performing loans (NPL) of the Brazilian banking system and macroeconomic factors, systemic risk, and banking concentration is empirically tested. In evaluating this relation, we use a dynamic specification with fixed effects, while using a panel data approach. The empirical results suggest that the banking concentration has a statistically significant impact on NPL, suggesting that more concentrated banking systems may improve financial stability. These results are important for the design of banking regulation policies.     

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.     

基于动态因子Copula模型的我国银行系统性风险度量

本文基于2007年至2019年我国14家上市银行的股票收益率,构建偏态t-分布动态因子Copula模型,利用时变荷载因子刻画单家银行与整个系统的相关性,计算联合风险概率作为系统性风险整体水平的度量,基于关联性视角提出了新的单家机构系统脆弱性和系统重要性度量指标——系统脆弱性程度和系统重要性程度。该方法充分考虑了银行个体差异性和系统的内在关联性以及收益率的厚尾性和非对称性,从而能够捕捉到更多的信息且兼具时效性。研究表明:银行机构在风险聚集时期相关程度更大,联合风险概率能够准确识别出系统性风险事件且在我国推行宏观审慎评估体系以后有明显降低;整体而言,大型商业银行系统重要性水平最高,同时风险抗压能力也最强;本文使用的度量方法降低了数据获取成本且更具时效性,有助于为宏观审慎差异化监管工作提供借鉴和参考。