银行同业业务、资产负债变化与金融市场流动性“悖论”：基于面板数据的实证研究

本文以银行同业业务和金融市场流动性为研究对象,试图厘清银行同业业务对市场流动性产生影响的作用机制,研究发现银行同业业务与流动性管理二者之间存在天然的“悖论”,体现在对资产负债期限错配的不同偏好上：期限错配是同业业务盈利的重要来源,而流动性管理的目标则是严格约束期限错配。本文还在系统构建金融市场流动性测度指标的基础上,借助面板数据,实证检验了不同规模银行、不同类型同业业务对金融市场流动性的影响大小,最后给出政策建议。     

Credit Risk in Interbank Networks

ABSTRACT

One of the most striking characteristics of modern financial systems is their complex interdependence, comprising a network of bilateral exposures in the interbank market, in which institutions with surplus liquidity can lend to those with a liquidity shortage. Empirical studies reveal that some interbank networks have features of scale-free networks. We explore the characteristics of financial contagion in networks whose distribution of links approaches a power law, using a model that defines banks’ balance sheets from information on network connectivity. By varying the parameters for the creation of the network, several interbank networks are built, in which the concentration of debt and credit comes from the distribution of links. The results suggest that networks that are more connected and have a high concentration of credit are more resilient to contagion than other types of networks analyzed.     

Interbank market failure and macro-prudential policies

This paper analyses the effects of several macro-prudential policy measures on the banking sector and its linkages to the macroeconomy. We employ a dynamic general equilibrium model with sticky prices, in which banks trade excess funds in the interbank lending market. We find that an increase in the liquidity requirement effectively reduces the impact of an interbank shock on the real and financial sector, while an increased capital requirement propagates only through nominal variables as inflation and interest rates. We conclude that stricter liquidity measures which limit inside money creation, dampen the severity of a breakdown in interbank lending. Targeting interbank financing directly through liquidity measures along with a moderate capital requirement generates lower welfare losses. We thereby provide a comprehensive rationale in favor of the regulatory measures in Basel III.     

Interbank liquidity risk transmission to large emerging markets in crisis periods

In this paper, we conduct two investigations regarding funding liquidity risk in large emerging economies: Brazil, Russia, India, China, and South Africa — BRICS. In the first, we track the relevance of monetary policy decisions originating in developed economies for interbank funding liquidity risk in BRICS economies during crisis periods by applying a time-varying parameter model in a Bayesian framework. The results indicate weak associations between interbank credit market and US monetary policy and market conditions. In contrast, the Federal Reserve's National Financial Conditions Index (NFCI) — a representative of the health of both real and financial sectors in the US — matters more. The temporal patterns of the results imply that key central banking decisions precede or coincide with low degrees of associations. In the second, we examine whether interbank credit crunch exerts an influence on market liquidity risk in BRICS economies using a Granger causality approach. The results reveal that interbank credit crunch depresses market liquidity in the corresponding domestic market and that the state of fear and credit market conditions in the US exert some influence in this regard. Overall, our findings hint at judicious market intervention and liquidity management by BRICS central banks.     

Balancing liquidity and returns through interbank markets: Endogenous interest rates and network structures

In this article, we develop a model of interbank lending based on liquidity and return on equity considerations of homogeneous banks. We derive the reservation prices of interbank lending and its properties before exploring how, because of an idiosyncratic liquidity shock, banks engage in bilateral lending to form an interbank network. We establish that the resulting networks exhibit realistic properties, including a core-periphery structure. Banks in the core and the periphery of this network differ not only in the amounts of interbank lending and borrowing but also in the interest rates applied to their transactions.     

Money and liquidity in financial markets

We argue that there is a connection between the interbank market for liquidity and the broader financial markets, which has its basis in demand for liquidity by banks. Tightness in the market for liquidity leads banks to engage in what we term “liquidity pull-back,” which involves selling financial assets either by banks directly or by levered investors. Empirical tests on the stock market are supportive. Tighter interbank markets are associated with relatively more volume in more liquid stocks; selling pressure, especially in more liquid stocks; and transitory negative returns. We control for market-wide uncertainty and in the process also contribute to the literature on portfolio rebalancing. Our general point is that money matters in financial markets.     

货币政策对银行间市场流动性影响效应的实证研究及启示

银行间货币市场是央行实施货币政策的重要平台，研究货币政策对银行间市场流动性的影响对于完善商业银行日常流动性管理具有重要意义。文章在设定银行间市场流动性测度指标与梳理货币政策工具对市场流动性的影响机制的基础上，分别使用事件分析法和时间序列模型对不同政策工具的影响效应进行实证分析，得出相关分析结论，并总结其对于完善商业银行日常流动性管理的启示。     

An early warning indicator system to monitor the unsecured interbank funds market

A core goal of regulators and financial authorities is to understand how market prices convey information on the financial health of its participants. From this viewpoint we build an Early-Warning Indicators System (EWIS) that allows for identifying those financial institutions perceived as risky counterparts by the participants of the interbank market. We use micro-level data from bilateral overnight unsecured loans performed in the interbank market between January 2011 and December 2014. The EWIS identifies those participants that systematically pay high prices for liquidity in this market. We employ coverage tests to estimate EWIS’ robustness and consistency. We find that financial institutions with an elevated frequency of signals tend to exhibit a net borrower liquidity position in the interbank market, hence suggesting they are facing recurrent liquidity needs. Those institutions also exhibit higher probability of insolvency measured by the Z-score indicator. Thus, our results support the existence of market discipline based on peer-monitoring. Overall, the EWIS may assist financial authorities in focusing their attention and resources on those financial institutions perceived by the market as those closer to distress.     

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.     

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.     

Monetary Policy Transmission with Interbank Market Fragmentation

This paper shows how interbank market fragmentation disrupts the transmission of monetary policy. Fragmentation is the fact that banks, depending on their country of location, have different probabilities of default on their interbank borrowings. Once fragmentation is introduced into standard theoretical models of monetary policy implementation, excess liquidity arises endogenously. This leads short-term interest rates to depart from the central bank policy rates. Using data on monetary policy operations, I show that this mechanism has been at work in the euro area since 2008. The model is used to analyze conventional and unconventional monetary policy measures.     

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.     

The effect of the interbank network structure on contagion and common shocks

This paper proposes a dynamic multi-agent model of a banking system with central bank. Banks optimize a portfolio of risky investments and riskless excess reserves according to their risk, return, and liquidity preferences. They are linked via interbank loans and face stochastic deposit supply. Comparing different interbank network structures, it is shown that money-centre networks are more stable than random networks. Evidence is provided that the central bank stabilizes interbank markets in the short run only. Systemic risk via contagion is compared with common shocks and it is shown that both forms of systemic risk require different optimal policy responses.     

银行间市场流动性与金融风险救助机制研究

文章从我国银行间市场结构特征出发,分析了近年来银行间市场利率和流动性大 幅波动的内在机理与原因。研究认为,塔形市场交易结构下,银行间市场存在流动性风险易聚 集不易分散的缺陷,且难以依靠“有形之手”得到弥补。文章结合塔形市场结构的特点建立矩 阵分析法,对40家金融机构资产负债表进行实证分析。结论印证了理论分析,即塔形市场交易 结构下风险冲击影响时间更长,且央行流动性救助效果降低,但流动性救助机制能降低风险对 中小型地方法人金融机构的冲击。因此,有必要建立流动性风险救助机制,弥补银行间市场客 观存在的缺陷,增强中小型地方法人金融机构抵御银行间市场流动性风险冲击的能力。     

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 impact of unconventional monetary policy on the market for collateral: The case of the French bond market

We consider the channel consisting in transferring the credit risk associated with refinancing operations between financial institutions to market participants. In particular, we analyze liquidity and volatility premia on the French government debt securities market, since these assets are used as collateral both in the open market operations of the ECB and on the interbank market. In our time-varying transition probability Markov-switching (TVTP-MS) model, we highlight the existence of two regimes. In one of them, which we refer to as the conventional regime, monetary policy neutrality is verified; in the other, which we dub the unconventional regime, monetary policy operations lead to volatility and liquidity premia on the collateral market. The existence of these conventional and unconventional regimes highlights some asymmetries in the conduct of monetary policy.     

Systemic liquidity shortages and interbank network structures

This paper aims to shed light on the systemic nature of liquidity risk and to propose a method for calculating systemic liquidity shortages. Our method incorporates not only direct liquidity shortages but also indirect liquidity shortages due to the knock-on effects through interbank linkages. We perform a simulation with a simple banking system model and find that a deficit bank can mitigate a liquidity shortage by holding more claims on a surplus bank. Meanwhile, a greater imbalance in liquidity positions across banks tends to aggravate the liquidity shortage of a deficit bank. According to comparative analysis between different types of network structures, a core-periphery network with a deficit money center bank gives rise to the highest level of systemic liquidity shortage, and a banking system becomes more vulnerable to liquidity shocks as its interbank network becomes more ill-matched.     

The interbank network across the global financial crisis: Evidence from Italy

This study examines the effects of the global financial crisis (GFC) on interbank market connectivity using network analysis. More specifically, using data on Italian banks’ bilateral interbank positions between 1998 and 2013, we analyze the impact of the following events on each bank's network centrality: the liquidity crisis in August 2007, the collapse of Lehman Brothers in September 2008, Eurosystem's long term refinancing operations (LTROs) between 2009 and 2012, the sovereign debt crisis in July 2011, and the announcement of Outright Monetary Transactions (OMT) in 2012. The results show that the 2007 liquidity crisis and especially the collapse of Lehman Brothers are associated with a marked reduction of the relative interconnectedness of the Italian banking sector (i.e., a shift in the distribution of banks’ centrality to the left, away from the most connected bank). In the following years, the system progressively recovered its initial patterns of integration among banks, which coincided with the main Eurosystem's monetary policy interventions. However, the average outcome conceals different results across banks, depending on their characteristics and initial positions within the system.     

Investigating risk contagion initiated by endogenous liquidity shocks: evidence from the US and eurozone interbank markets

This paper investigates liquidity spillovers between the US and European interbank markets during turbulent and tranquil periods. We show that an endogenous model with time-varying transition probabilities is effective in describing the propagation of liquidity shocks within the interbank market, while predicting liquidity crashes characterised by changed dynamics. We show that liquidity shocks, originating from movements of the spread between the Asset Backed Commercial Paper and T-bill, drive regime changes in the euro fixed-float OIS swap rate. Our results support the idea of endogenous contagion from the US money market to the eurozone money market during the global financial crisis.     

Bank market power,asset liquidity and funding liquidity: International evidence

Our investigation of the association between bank market power and liquidity in 101 countries reveals that a bank's initial gains of market power lead to increases in bank liquidity, but does so at a diminishing rate. Beyond an empirically determined threshold, further increases in market power are inversely associated with bank liquidity. From a cross-sectional viewpoint, banks that lack market power hold more liquid assets and are net lenders in the interbank market. In contrast, dominant banks hold less liquid assets and are net interbank borrowers. For a given level of market power, ceteris paribus, developed nation banks hold less asset liquidity and obtain more interbank funding liquidity than their developing country peers. These results remain equally relevant during the 2007–2009 global financial crisis (GFC).