影子银行的发展及其监管

自上个世纪末以来,影子银行快速发展,资产规模已接近传统银行体系.影子银行的风险被认为是造成2008年全球金融危机的重要原因,各国和国际金融机构近年纷纷出台加强影子银行监管的措施,试图改变过去监管缺失的状态.和国外影子银行以资产证券化为核心不同,我国影子银行的主要功能是作为融资渠道.因此,我国要借鉴国外影子发展和监管的经验,正确看待影子银行的作用,引导其规范发展并将其作为银行体系的有益补充.     

A Time Series Analysis of Financial Fragility in the UK Banking System

This paper extends the model proposed by Goodhart, Sunirand, and Tsomocos (2004, 2005, 2006) to an infinite horizon setting. Thus, we are able to assess how the model conforms with the time series data of the UK banking system. We conclude that, since the model performs satisfactorily, it can be readily used to assess financial fragility given its flexibility, computability, and the presence of multiple contagion channels and heterogeneous banks and investors. JEL Classification Numbers C68, E4, E5, G11, G21 We are grateful to seminar participants at the Bank of England, European Central Bank, University of Oxford, University of Pireaus, 59th International Atlantic Economic Conference, London and especially an anonymous referee for helpful comments and suggestions     

How likely is contagion in financial networks?

Interconnections among financial institutions create potential channels for contagion and amplification of shocks to the financial system. We estimate the extent to which interconnections increase expected losses and defaults under a wide range of shock distributions. In contrast to most work on financial networks, we assume only minimal information about network structure and rely instead on information about the individual institutions that are the nodes of the network. The key node-level quantities are asset size, leverage, and a financial connectivity measure given by the fraction of a financial institution’s liabilities held by other financial institutions. We combine these measures to derive explicit bounds on the potential magnitude of network effects on contagion and loss amplification. Spillover effects are most significant when node sizes are heterogeneous and the originating node is highly leveraged and has high financial connectivity. Our results also highlight the importance of mechanisms that go beyond simple spillover effects to magnify shocks; these include bankruptcy costs, and mark-to-market losses resulting from credit quality deterioration or a loss of confidence. We illustrate the results with data on the European banking system.     

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.     

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.     

Can CoCo-bonds mitigate systemic risk?

After the 2008 financial crisis, the idea of contingent convertible (CoCo) capital was revived as a means to stabilize individual banks, and hence the entire banking system. The purpose of this paper is to empirically test, whether CoCo-bonds indeed improve the stability of the banking system and reduce systemic risk. Using the broadly applied SRISK metric, we obtain contradicting results, which are based on the accounting of the CoCo-bond as debt or equity. This observation is problematic, as CoCo-bonds generally increase the loss-absorbing capacity of a bank. We remedy this shortcoming by proposing an adjustment to the original SRISK formula. Using empirical tests, we show that the undue disparity has been solved by our adjustment, and that CoCo-bonds reduce systemic risk, irrespective of their accounting. Our results are robust to different parametrizations and accounting standards, as well as issuance effects.     

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).     

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.     

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.     

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.     

Diversification disasters

The recent financial crisis has revealed significant externalities and systemic risks that arise from the interconnectedness of financial intermediaries’ risk portfolios. We develop a model in which the negative externality arises because intermediaries’ actions to diversify that are optimal for individual intermediaries may prove to be suboptimal for society. We show that the externality depends critically on the distributional properties of the risks. The optimal social outcome involves less risk-sharing, but also a lower probability for massive collapses of intermediaries. We derive the exact conditions under which risk-sharing restrictions create a socially preferable outcome. Our analysis has implications for regulation of financial institutions and risk management.     

尾部风险研究进展与评述

由于部分业务、部门或市场的尾部风险溢出不仅会引发金融体系的“多米诺骨牌”效应,而且会对实体经济产生巨大负外部性,因此尾部风险事件极易引起金融市场震荡。鉴于此,识别与监测尾部风险是有效防控系统性金融风险爆发与传染的起点。本文首先以全球金融危机为节点,根据文献厘清尾部风险测度指标在危机前后的脉络。其次,介绍与尾部风险传染密切相关的尾部风险相依、金融关联网络的相关研究进展,在此基础上对尾部风险溢出强度及溢出方向展开讨论。再次,本文归纳了引发尾部风险溢出的宏观、中观和微观层面的影响因素以及尾部风险管理的路径选择。最后,对当前及未来尾部风险相关研究进行评述与展望。据此,力求为我国进一步提高防范化解金融风险能力、统筹推进疫情防控和经济社会发展、促进国民经济稳健运行和良性循环提供借鉴。