Modelling the emergence of the interbank networks

Interbank contagion has become a buzzword in the aftermath of the financial crisis that led to a series of shocks to the interbank market and to periods of pronounced market disruptions. However, little is known about how interbank networks are formed and about their sensitivity to changes in key bank parameters (for example, induced by common exogenous shocks or by regulatory initiatives). This paper aims to shed light on these issues by modelling endogenously the formation of interbank networks, which in turn allows for checking the sensitivity of interbank network structures and hence, their underlying contagion risk to changes in market-driven parameters as well as to changes in regulatory measures such as large exposures limits. The sequential network formation mechanism presented in the paper is based on a portfolio optimization model, whereby banks allocate their interbank exposures while balancing the return and risk of counterparty default risk and the placements are accepted taking into account funding diversification benefits. The model offers some interesting insights into how key parameters may affect interbank network structures and can be a valuable tool for analysing the impact of various regulatory policy measures relating to banks’ incentives to operate in the interbank market.     

Conditional risk, return and contagion in the banking sector in asia

This paper investigates risk and return in the banking sector in three Asian markets of Taiwan, China and Hong Kong. The study focuses on the risk-return relation in a conditional factor GARCH-M framework that controls for time-series effects. The factor approach is adopted to incorporate intra-industry contagion and an analysis of spillovers between large banks and small banks. Finally, the study provides evidence on these relations before and after the Asian financial crisis of 1997. The results are generally consistent across the markets and with expectations.     

Optimal equity infusions in interbank networks

We study optimal equity infusions into a financial network prone to the risk of contagious failures, which may be due to insolvency or to bank runs by short term creditors. Bank runs can be triggered by failures of connected banks.Under complete information on interbank linkages, we show that the problem reduces to a combinatorial optimization problem. Subject to budget constraints, the government chooses the set of minimal cost whose survival induces the maximum network stability. Our results demonstrate that the optimal equity infusion might significantly mitigate failure contagion risk and stabilize the system. In the case of partial information on the network, the controllers’ focus swiftly changes from preventing insolvencies to preventing runs by short term creditors.     

Overview on the recent developments of banking and risk management

This note aims at focusing at the recent developments in banking and risk management with a particular focus on empirical analyses about banks’ regulation and financial risk. It notably describes a financial atmosphere whereby, in response to the US subprime mortgage crisis and the continuing stress in financial markets, policymakers developed alternative monetary policies and regulators pursued different reforms and new regulations to overcome the effects of this crisis. To better understand these different changes and reforms, this note presents the 9 best articles selected from the second International Workshop on Market Microstructure and Nonlinear Dynamics (Paris, June 4–5, 2015, www.fmnd.fr) that focused on these topics. Interestingly, through these different contributions, this special issue has developed new insights about methodologies and quantitative risk management techniques that assess the effects of the financial crisis, explain its different challenges, and suggest some solutions.     

基于信用链接的银行网络风险传染研究述评

对传染性银行风险的研究一直是重要的问题,本文全面介绍了基于信用链接的银行网络中风险传染研究的最新成果。该领域研究主要是从两个方面来展开,一方面是从经济学的角度对银行网络中风险传染进行研究;另一方面是从经济物理的角度,通过对银行网络结构和银行主体建模,并用仿真的方法研究银行网络中的风险传染问题。本文对目前研究现状存在的不足进行了评述,并进一步指出了未来的研究方向。     

Default contagion and systemic risk in loan guarantee networks

This paper studies systemic risk in the Chinese debt market stemming from inter‐corporate loan guarantees using field data from Zhejiang Province. We apply a weighted and directed network model to analyse the implications for default contagion and systemic risk under different stress testing scenarios. The empirical results indicate that the topology of the loan guarantee network is close to a ‘scale‐free’ structure, which is known to be robust against accidental failures but vulnerable to coordinated attacks. Hence, the network is able to cope with idiosyncratic shocks resulting from single company failures, but can easily suffer from more widespread contagion if a group of systemically important companies are hit by a targeted shock. We further demonstrate that within our sample of small and medium‐sized enterprise (SME) companies, increasing leverage reduces network stability and exacerbates the effects of contagion. More lenient bank lending policies increase the survival rate of sample companies and thereby reduce the losses from default contagion.     

Contagion and banking crisis – International evidence for 2007–2009

Policy makers aim to avoid banking crises, and although they can to some extent control domestic conditions, internationally transmitted crises are difficult to tackle. This paper identifies international contagion in banking during the 2007–2009 crisis for 54 economies. We identify three channels of contagion – systematic, idiosyncratic and volatility – and find evidence for these in 45 countries. Banking crises are overwhelmingly associated with the presence of both systematic and idiosyncratic contagion. The results reveal that crisis shocks transmitted from a foreign jurisdiction via idiosyncratic contagion increase the likelihood of a systemic crisis in the domestic banking system by almost 37 percent, whereas increased exposure via systematic contagion does not necessarily destabilize the domestic banking system. Thus while policy makers and regulatory authorities are rightly concerned with the systematic transmission of banking crises, reducing the potential for idiosyncratic contagion can importantly reduce the consequences for the domestic economy.     

Explaining banking stability in Sub-Saharan Africa

The study examined banking stability in Sub-Saharan Africa. The results reveal that banking spread (Net Interest Margin – NIM) is the main determinant of stability and the major means to achieve stability during crises periods. We however find the existence of a threshold effect in NIM.Crises in the banking sector consistently showed to reduce stability. While the results show that high percentage of foreign banks reduce stability, we find foreign banks help stabilize the banking sector in periods of crises. The results show that diversification could also have a positive impact on stability (Z-score) even though this relationship was not robust enough. The results also largely support the competition-fragility view. Particularly, we find that less competition during crises periods can help improve stability. Again, we find evidence for both concentration-stability and concentration-fragility hypotheses depending on the stability measure used. We however find that when large banks in concentrated markets are well regulated, stability could be improved. Weak regulatory environment reduces stability (Z-score) directly and matters during crises periods. Our results are robust to the use of different indicators of stability and estimation methods.     

Systemic risk and dynamics of contagion: a duplex inter-bank network

This paper constructs a duplex banking network formed by credit relationships and information interaction via the banks’ balance sheet to model the structure of systemic risk and investigate the dynamic mechanism of contagion in terms of default and liquidity infection along with the factors that affect the extent of the contagion. We systematically explain the role that duplex banking networks play in different aspects of risk contagion. Through theoretical analysis and simulations, we conclude that asymmetric information interaction would increase the inflexibility of the system, which leads to liquidity shortage and possibly the collapse of the whole market. The weakness of systemic risk in the interior of the complex banking system can be characterized by the partial discount factor using illiquid assets in the information network. By improving the connectedness of the information network of the duplex networks, the spread of contagion can be partially slowed.     

Introduction to recent research topics in banking and finance

This note introduces a set of papers that have been presented to the third International Symposium on Computational Economics and Finance (ISCEF), organized in Paris on April 10–12, 2014, focusing on topics in banking and financial markets. This selection of papers emphasizes the role of the development of research in quantitative finance that benefited from the progress in econometric modeling and the availability of high frequency data. These studies carried in the context of the global financial crisis provide different interesting findings enabling to better understand financial market dynamics and banking sectors. We briefly analyze in this note their methodologies and discuss their empirical findings.     

Bank capital,interbank contagion,and bailout policy

This paper develops a theoretical framework in which asset linkages in a syndicated loan agreement can infect a healthy bank when its partner bank fails. We investigate how capital constraints affect the choice of the healthy bank to takeover or liquidate the exposure held jointly with the failing bank, and how the bank’s ex ante optimal capital holding and possibility of contagion are affected by anticipation of bail-out policy, capital requirements and the joint exposure. We identify a range of factors that strengthen or weaken the possibility of contagion and bailout. Recapitalization with common stock rather than preferred equity injection dilutes existing shareholder interests and gives the bank a greater incentive to hold capital to cope with potential contagion. Increasing the minimum regulatory capital does not necessarily reduce contagion, while the requirement of holding conservation capital buffer could increase the bank’s resilience to avoid contagion.     

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.     

The political economy of relationship banking

In the aftermath of the global financial crisis, banks need to reevaluate their position in light of profound changes in the economic, social, and political landscape. On the one hand, we emphasize the benefits of relationship banking, which establishes close contact with bank customers. Through a long-term orientation, relationship banking aligns incentives and supports the long-term needs of bank customers, leading to reduced inequality and greater firm innovation. On the other hand, the interaction between politics and relationship banking can have dark sides. First, with new borders arising and competition in banking affected, relationship banking might be particularly prone to political interference. Second, a shock to the relationship bank can be transmitted to its borrowers. We analyze how relationship banking can overcome its drawbacks.     

Mapping the UK interbank system

We present new evidence on the structure of interbank connections across key markets: derivatives, marketable securities, repo, unsecured lending and secured lending. Taken together, these markets comprise two networks: a network of interbank exposures and a network of interbank funding. Network structure varies across and within these two networks, for reasons related to markets’ different economic functions. Credit risk and liquidity risk therefore propagate in the interbank system through different network structures. We discuss the implications for financial stability.     

Pandemic-driven financial contagion and investor behavior: Evidence from the COVID-19

This paper studies the pandemic-driven financial contagion during the COVID-19 period and the impact of investor behavior on it by constructing three types of direct behavior measurements based on Google search volumes. More specifically, using a sample of 26 major stock markets around the world during the COVID-19 pandemic, we construct a non-linear financial contagion network via a dynamic mixture copula-EVT (extreme value theory) model to quantitatively detect and measure the complex nature of pandemic-driven financial contagion. Furthermore, through constructing direct investor behavior measurements including investor attention, sentiment, and fear, we find investor behavior plays an important role in explaining pandemic-driven financial contagion. We also find that the impacts of investor behavior on the pandemic-driven financial contagion are heterogeneous under several different settings, including market conditions, market development levels, regional subsets, and contagion directions.     

银行跨境风险监管改革的国际趋向及对策建议

近年来,国际上针对银行跨境风险兴起了重构跨境监管框架的热潮,成为后危机时代银行监管体系改革的重要组成部分。本文分析了跨境监管的模式与困难,以及近期国际上跨境监管的趋势及局限,在此基础上,探讨实现有效跨境风险监管合作的具体途径,并结合我国实际,提出了若干改进和完善我国跨境银行监管的对策建议。     

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.     

Financial globalisation uncertainty/instability is good for financial development

This study assesses the effect of time-dynamic financial globalisation uncertainty on financial development in 53 African countries for the period 2000–2011. The empirical evidence is based on the Generalised Method of Moments with forward orthogonal deviations. The following findings are established. First, financial globalisation uncertainty does not significantly affect money supply, financial system deposits and financial size. Second, the uncertainty increases banking system efficiency, banking system activity and financial system activity. Moreover, the positive effects are consistently driven by above-median uncertainty levels. It follows that uncertainty in foreign capital flows may be a disguised advantage for domestic financial development, especially in dealing with the substantially documented issue of surplus liquidity in African financial institutions. Additionally, the sceptical view in the financial globalisation literature that ‘allocation efficiency’ is only plausible in the absence of uncertainty/instability is not substantiated by the findings. Justifications for the nexuses and policy implications are discussed.     

Model uncertainty and systematic risk in US banking

This paper uses Bayesian Model Averaging to examine the driving factors of equity returns of US Bank Holding Companies. BMA has as an advantage over OLS that it accounts for the considerable uncertainty about the correct set (model) of bank risk factors. We find that out of a broad set of 12 risk factors only the market, real estate, and high-minus-low Fama–French factors are reliably related to US bank stock returns over the period 1986–2010. Other factors are either only relevant over specific subperiods or for subsets of bank holding companies. We discuss the implications of our findings for empirical banking research.     

This time is different: Causes and consequences of British banking instability over the long run

This paper addresses three questions: (1) How severe were the episodes of banking instability experienced by the UK over the past two centuries? (2) What have been the macroeconomic indicators of UK banking instability? and (3) What have been the consequences of UK banking instability for the cost of credit? Using a unique dataset of bank share prices from 1830 to 2010 to assess the stability of the UK banking system, we find that banking instability has grown more severe since the 1970s. We also find that interest rates, inflation, lending growth, and equity prices are consistent macroeconomic indicators of UK banking instability over the long run. Furthermore, utilising a unique dataset of corporate-bond yields for the period 1860 to 2010, we find that there is a significant long-run relationship between banking instability and the credit-risk premium faced by businesses.