Credit Contagion Channels: Market Microstructure Evidence from Lehman Brothers’ Bankruptcy

Immediately after Lehman Brothers’ bankruptcy, many firms disclosed their financial exposure (or lack thereof) to Lehman. This offers a clean setting to test two credit contagion channels through which a financial firm's bankruptcy can affect other firms—“counterparty risk” and “information transmission” channels. Using market microstructure variables to measure the various dimensions of contagion effects, we provide robust evidence supporting the significance of counterparty risk. Firms with exposure to Lehman suffered more severe negative effects—wider bid‐ask spread, higher price impact, greater information asymmetry, and greater selling pressure—than unexposed firms. We find mixed evidence regarding the information transmission hypothesis.     

Political foundations of the lender of last resort: A global historical narrative

This paper offers a historical perspective on the evolution of central banks as lenders of last resort (LOLR). Countries differ in the statutory powers of the LOLR, which is the outcome of a political bargain. Collateralized LOLR lending as envisioned by Bagehot (1873) requires five key legal and institutional preconditions, all of which required political agreement. LOLR mechanisms evolved to include more than collateralized lending. LOLRs established prior to World War II, with few exceptions, followed policies that can be broadly characterized as implementing “Bagehot's Principles”: seeking to preserve systemic financial stability rather than preventing the failure of particular banks, and limiting the amount of risk absorbed by the LOLR as much as possible when providing financial assistance. After World War II, and especially after the 1970s, generous deposit insurance and ad hoc bank bailouts became the norm. The focus of bank safety net policy changed from targeting systemic stability to preventing depositor loss and the failure of banks. Statutory powers of central banks do not change much over time, or correlate with country characteristics, instead reflecting idiosyncratic political histories.     

On the Economics of Postassessments in Insurance Guaranty Funds: A Stakeholders’ Perspective

This article proposes a model that suggests there are contagion effects among members of an insurance guaranty fund when postassessments are charged to all other insurers upon the failure of a member company. Indeed, these extraordinary payments are shown to increase the default rate of other firms in the industry, ultimately lowering the value of corporate claims as well as government tax claims. The model is also used to examine the efficiency of different recoupment mechanisms (both existing and new) used by regulators and insurers to potentially reduce these contagion effects. Analysis allows us to stipulate the conditions under which a “tax carryforward” provision could be more efficient than the usual recoupment mechanisms known as “premium rate surcharge” and “premium tax credit.”     

Financial contagion and the role of the central bank

We investigate the role of a central bank (CB) in preventing and avoiding financial contagion. The CB, by imposing reserve requirements on the banking system, trades off the cost of reducing the resources available for long-term investment with the benefit of raising liquidity to face an adverse shock that could cause contagious crises. We argue that contagion is not due to the structure of the interbank deposit market, but to the impossibility to sign contracts contingent on unforeseen contingencies. As long as incomplete contracts are present, the CB may have a useful role in curbing contagion. Moreover, the CB allows the banking system to reach first-best allocation in all the states of the world when the notion of incentive-efficiency is considered. If the analysis is restricted to constrained-efficiency, the CB still avoids contagion without, however, reaching first-best consumption allocation. The model provides a rationale for reserve requirements without the presence of fiat money or asymmetric information.     

The Global Crisis and Equity Market Contagion

We analyze the transmission of the 2007 to 2009 financial crisis to 415 country‐industry equity portfolios. We use a factor model to predict crisis returns, defining unexplained increases in factor loadings and residual correlations as indicative of contagion. While we find evidence of contagion from the United States and the global financial sector, the effects are small. By contrast, there has been substantial contagion from domestic markets to individual domestic portfolios, with its severity inversely related to the quality of countries’ economic fundamentals. This confirms the “wake‐up call” hypothesis, with markets focusing more on country‐specific characteristics during the crisis.     

The credit quality channel: Modeling contagion in the interbank market

We propose an algorithm to model contagion in the interbank market via what we term the “credit quality channel”. In existing models on contagion via interbank credit, external shocks to banks often spread to other banks only in case of a default. In contrast, shocks are transmitted also via asset devaluations and deteriorations in the credit quality in our algorithm. First, the probability of default (PD) of those banks directly affected by some shock increases. This increases the expected loss of the credit portfolios of the initially affected banks’ counterparties, thereby reducing the counterparties’ regulatory capital ratio. From a logistic regression we estimate the increase in the counterparties’ PD due to a reduced capital ratio. Their increased PDs in turn affect the counterparties’ counterparties, and so on. This coherent and flexible framework is applied to the bilateral interbank credit exposure of the entire German banking system in order to examine policy questions. For that purpose, we propose to measure the potential cost of contagion of a given shock scenario by the aggregated regulatory capital loss computed in our algorithm.     

基于共同冲击和异质风险叠加传导的风险传染研究——来自中国上市银行网络的传染模拟

本文将银行系统遭遇外部共同冲击作为研究起点,建立了一个共同冲击和异质风险交互传导与放大的简化模型,冲击的传导包括“原始冲击”、“增量冲击”和“违约冲击”三个风险传染阶段。基于2018年我国15家上市银行的股票收益率和年报数据、2006年至2018年的银行评级数据,本文构建了贝叶斯分层图模型和银行间拆借矩阵,并利用蒙特卡洛模拟测度不同触发银行所引发的系统性风险损失、单个银行的系统性风险杠杆能力(文中定义为“传染乘数”指标)以及政府监管介入的效果。模拟结果显示:共同冲击损失远大于异质风险损失;规模和网络关联性是决定传染乘数的重要因素,且当规模因素不突出时,网络关联性对传染乘数的决定作用相对更强,极容易出现小规模、高关联性银行具有较高的传染乘数;当银行风险资产损失率在10%至25%之间时,造成系统性风险损失的杠杆能力普遍增强;政府监管介入能较好地降低系统性风险。本研究的相关结论为系统性风险的监管设计提供经验证据和参考。     

Tail risk measurement in crypto-asset markets

The paper examines the relationships among market assets during stressful times, using two recently proposed econometric modeling techniques for tail risk measurement: the extreme downside hedge (EDH) and the extreme downside correlation (EDC). We extend both measures taking into account the sensitivity of asset's return to innovations not only from the overall market index, but also from its components, by means of network modeling. Applying our proposal to the cryptocurrencies market, we find that crypto-assets can be clustered in two groups: speculative assets, such as Bitcoin, which are mainly “givers” of tail contagion; and technical assets, such as Ethereum, which are mainly “receivers” of contagion.     

Bank monitoring incentives and optimal ABS

The paper examines a continuous-time delegated monitoring problem between competitive investors and an impatient bank monitoring a pool of long-term loans subject to Markovian “contagion.” Moral hazard induces a foreclosure bias unless the bank is compensated with the right incentive-compatible contract. Fees are paid when the bank’s performance is on target and liquidation arises when the bank’s performance is sufficiently poor. I show that the optimal contract can be implemented with a whole loan sale involving both credit risk retention based on ABS credit default swaps and credit enhancement in the form of a reserve account. The optimal securitization bears out rulemaking recently proposed in the wake of the Dodd-Frank Act on a number of controversial provisions. I argue that further efficiency gains could be reaped by extending the role of the “premium capture” account into a liquidity buffer capturing performance-based compensation as a way of increasing skin in the game over the life of the transaction.     

Correlation in corporate defaults: Contagion or conditional independence?

We revisit a method used by Das et al. (2007) (DDKS) who jointly test and reject a specification of firm default intensities and the doubly stochastic assumption in intensity models of default. The method relies on a time change result for counting processes. With an almost identical set of default histories recorded by Moody’s in the period from 1982 to 2006, but using a different specification of the default intensity, we cannot reject the tests based on time change used in DDKS. We then note that the method proposed by DDKS is mainly a misspecification test in that it has very limited power in detecting violations of the doubly stochastic assumption. For example, it will not detect contagion which spreads through the explanatory variables “covariates” that determine the default intensities of individual firms. Therefore, we perform a different test using a Hawkes process alternative to see if firm-specific variables are affected by occurrences of defaults, but find no evidence of default contagion.     

The anatomy of sovereign risk contagion

The channels for the cross-border propagation of sovereign risk in the international sovereign debt market are analysed. Identifying sovereign credit events as extraordinary jumps in CDS spreads, we distinguish between the immediate effects of such events and their longer term spillover effects. To analyse “fast and furious” contagion, we use daily CDS data to conduct event studies around a total of 89 identified credit events in a global country sample. To analyse “slow-burn” spillover effects, we apply a multifactor risk model, distinguishing between global and regional risk factors. We find that “fast and furious” contagion has been primarily a regional phenomenon, whilst “slow-burn” spillover effects can often be global in scope, especially those of the recent European debt crisis. The global risk factors are found to be driven by investor risk appetites and debt levels, whilst the regional factors depend on economic fundamentals of countries within a region.     

Leading the herd: evidence from mutual funds’ buy and sell decisions

This article investigates whether a mutual fund’s performance is related to its herding behavior. Using the methodology of Sias (Rev Finance Stud 17:165–206, 2004), we develop a measure to capture the magnitude that a fund’s buy (sell) decisions are leading other funds’ buys (sells), and find that a fund’s performance is positively (negatively) related to its “buy leading” (“sell leading”). We interpret these findings as evidence that “buy leaders” (“sell leaders”)’ performance benefits (suffers) from the positive (negative) price effect associated with buy (sell) herds. Additionally, we find a positive relationship between fund performance and valuation-motivated “buy leading”, while we find weak evidence on the relationship between performance and valuation-motivated “sell leading”. We interpret these results as evidence that leading funds’ outperformance is due, in part, to their ability to value stocks.     

Getting the Right Mix of Capital and Cash Requirements in Prudential Bank Regulation*

Cash reserve requirements are useful as a broadly conceived prudential tool, not just as a narrowly focused means of limiting the risks associated with illiquidity. Indeed, illiquidity risk is neither a necessary nor a sufficient condition for establishing bank liquidity requirements. The primary means of mitigating the systemic costs of bank illiquidity risk is the creation of an effective lender of last resort (LOLR). But instead of focusing narrowly on bank funding risks when designing liquidity requirements, regulators should consider tradeoffs among capital requirements, liquidity requirements, and LOLR policies for achieving the broader prudential goal of limiting bank default risk. When considering the optimal tradeoff between capital ratios and cash ratios as prudential requirements, five “frictions” are identified that favor the use of one or the other: (1) the adverse‐selection costs of raising equity (which favors the use of cash); (2) the opportunity cost of forgone abnormal profits (or “quasi rents”) from lending (which favors the use of capital); (3) the limited verifiability of loan outcomes (which favors the use of cash); (4) the moral hazard that results from costly or postponed loss recognition, given the incentive for risk shifting in bad states (which favors the use of cash); and (5) the prospect of changes in the risk environment (which favors cash since it creates greater option value for maintaining targeted default risk with lower adjustment costs in the face of changing loan risk or illiquidity risk). When viewed from the perspective of achieving the main prudential goal of controlling default risk at a minimum social cost, capital requirements have some limitations that favor liquidity requirements, and vice versa. And thus the optimal regulatory policy will combine liquidity and capital requirements.     

全球股票市场间风险传染的测度、监管及预警

近年来,伴随金融一体化程度的加深,全球各股票市场间风险传染的动态复杂性加剧,其准确测度、高效监管及实时预警已成为优先事项。本研究选取全球21个代表性股票市场作为分析样本,首先基于广义向量自回归模型的滚动估计准确测度其间风险动态传染的高维网络序列,进一步借由矩阵值因子模型来稳健收缩上述序列,以探究其潜在动态核心结构,从而实现高效监管。最后,通过向量自回归模型的预测功能实现对全球股票市场间风险传染的实时预警。研究表明,全球股票市场间风险传染具有时变性,其监管与预警可通过少数与地理区域高度相关的风险区域间的动态传染关系及内部的市场构成来刻画。与此同时,我们发现中国内地等新兴市场的重要地位逐渐凸显。本文研究结论可为有效防范与化解金融风险提供有益参考。     

全球股票市场间风险传染的测度、监管及预警

近年来,伴随金融一体化程度的加深,全球各股票市场间风险传染的动态复杂性加剧,其准确测度、高效监管及实时预警已成为优先事项。本研究选取全球21个代表性股票市场作为分析样本,首先基于广义向量自回归模型的滚动估计准确测度其间风险动态传染的高维网络序列,进一步借由矩阵值因子模型来稳健收缩上述序列,以探究其潜在动态核心结构,从而实现高效监管。最后,通过向量自回归模型的预测功能实现对全球股票市场间风险传染的实时预警。研究表明,全球股票市场间风险传染具有时变性,其监管与预警可通过少数与地理区域高度相关的风险区域间的动态传染关系及内部的市场构成来刻画。与此同时,我们发现中国内地等新兴市场的重要地位逐渐凸显。本文研究结论可为有效防范与化解金融风险提供有益参考。     

Budget or target: the choice between input and output strategies

In many competitive environments, players need to commit either to a specific goal they will achieve (an output target) or to the resources they are willing to expend in pursuit of that goal (an input budget). We model this situation as a two‐stage game where players may compete either by setting input and letting their output follow from the environment (“leading input”), or by setting output and letting the input levels required to support the output targets follow (“leading output”). We show that when each player's output is increasing (decreasing) in his rival's input, leading input (output) dominates leading output (input).     

Machine learning as an early warning system to predict financial crisis

This paper studies on “Early Warning Systems” (EWS) by investigating possible contagion risks, based on structured financial networks. Early warning indicators improve standard crisis prediction models performance. Using network analysis and machine learning algorithms we find evidence of contagion risk on the dates where we observe significant increase in correlations and centralities. The effectiveness of machine learning reached 98.8%, making the predictions extremely accurate. The model provides significant information to policymakers and investors about employing the financial network as a useful tool to improve portfolio selection by targeting assets based on centrality.     

金融危机跨国传染的实证检验——以美国金融危机为例

论文使用包括美国在内的28个经济体的股票指数的日收益率,进行相关系数及其费雪Z转换来检验美国金融危机的跨国传染效应;并运用单因素模型回归来验证纯传染效应的存在以及用经异方差调整后的相关系数对此纯传染效应进一步判断,分析结果表明:中国大陆和香港地区在本次危机中不仅存在金融危机传染效应,而且存在金融危机纯传染效应,而另外8个存在金融危机传染效应的经济体则不存在纯传染效应。     

Regime-Dependent Determinants of China’s Sovereign Credit Default Swap Spread

We study the determinants of China’s sovereign credit default swap (CDS) spread in a regime-switching framework. This framework allows us to identify potential cross-asset-class contagion from global financial markets to China. To avoid endogeneity biases coming from domestic costs of sovereign default, we model domestic financial indicators as endogenous variables and estimate the regime-switching model with instrumental variables. We find strong evidence of cross-asset-class contagion but no evidence of contagion from sovereign CDS markets of China’s major trade partners (the European Union, Japan, and the United States).     

Contagion of accounting methods: evidence from stock option expensing

I examine how a firm’s accounting methods can be influenced by the choices of other firms, which I label contagion. I model accounting method choice as a combination of intrinsic propensities to adopt a method and contagion effects. I predict contagion of accounting methods occurs for two reasons: (1) adoption decisions of other firms are informative for the adoption decision, and (2) prior adoptions change the net benefits of the decision. I test these predictions in the stock option expensing setting where firms had the choice to use the intrinsic or fair value method. Using a firm-level diffusion model, I document evidence consistent with my predictions.