Financial intermediation in an overlapping generations model with transaction costs

We analyze an overlapping generations economy where agents interact to share liquidity risk. We show that a pure exchange economy has excessive trade in equilibrium because agents interact to rebalance their portfolios. Intergenerational financial intermediaries reduce the number of interactions because agents only transact when they face liquidity needs. In the absence of asset risk, intermediaries match redemptions with deposits and dividends, and never sell assets. If the economy is subject to transaction costs, the intermediated economy can sustain higher stationary investment and welfare. We also find that dead weight transaction costs can increase welfare because it protects banks from interbank arbitrage and dampens the inherent cyclicality of market economies.     

Systemic liquidity contagion in the European interbank market

Systemic liquidity risk, defined by the International Monetary Fund as “the risk of simultaneous liquidity difficulties at multiple financial institutions,” is a key topic in financial stability studies and macroprudential policy-making. In this context, the complex web of interconnections of the interbank market plays the crucial role of allowing funding liquidity shortages to propagate between financial institutions. Here, we introduce a simple yet effective model of the interbank market in which liquidity shortages propagate through an epidemic-like contagion mechanism on the network of interbank loans. The model is defined by using aggregate balance sheet information of European banks, and it exploits country and bank-specific risk features to account for the heterogeneity of financial institutions. Moreover, in order to obtain the European-wide topology of the interbank network, we define a block reconstruction method based on the exchange flows between the various countries. We show that the proposed contagion model is able to estimate systemic liquidity risk across different years and countries. Results suggest that our effective contagion approach can be successfully used as a viable alternative to more realistic but complicated models, which not only require more specific balance sheet variables with high time resolution but also need assumptions on how banks respond to liquidity shocks.

     

Systemic risk mitigation in financial networks

We propose a multi-period clearing framework, where the level of systemic risk is mitigated through the provision of liquidity assistance. The interbank liability network evolves stochastically over time, and assets of defaulted banks are sold to qualified banks within the network through a first-price sealed-bid auction. We find that policies targeting systemically important banks are more effective in core-periphery network structures, whereas those maximizing the total liquidity in the system are preferred in random network configurations. We assess sensitivity of systemic risk to variations in interbank liabilities as well as to their correlation structure.     

Interbank loans,collateral and modern monetary policy

This study develops a novel agent-based model of the interbank market with endogenous credit risk formation mechanisms. We allow banks to exchange funds through unsecured and secured transactions, which facilitates the flow of funds to the most profitable investment projects. Risk premiums result from banks׳ forecasting rules and depend on past performance of the benchmark risk factors and interest rates. Our model confirms basic stylized facts of the interbank interest rates and volumes. We also find that network structures within the secured market segment are characterized by the presence of dealer banks, while we do not observe similar patterns in the unsecured market. We perturb the model with exogenous shocks and policy scenarios which correspond to unconventional monetary policies.     

Pricing in the Norwegian Interbank Market – the Effects of Liquidity and Implicit Government Support

We investigate the effects of central bank liquidity and possible implicit government guarantees against default on Norwegian overnight interbank interest rates. We conduct an econometric study of these interest rates over the period 2006–09, which includes the sharp fall in interbank trading during the financial crisis. Our findings suggest relatively lower funding costs for banks of systemic importance, particularly for banks with many and valuable linkages to other banks. Moreover, interest rates are found to depend not only on overall liquidity in the interbank market, but on its distribution among banks as well. There is also evidence of stronger effects on interest rates of systemic importance, creditworthiness and liquidity demand and supply factors during the financial crisis.     

Transaction taxes, greed and risk aversion in an agent-based financial market model

Recent agent-based financial market models came to the result that taxing financial transactions does not per se increase financial stability and that the response of volatility and misalignments to rising tax rates seem to be u-shaped. Moreover, greed and the risk appetite of traders are often blamed for financial instability and there is no evidence how greed and risk aversion affect the effectiveness of regulations in financial markets. We aim to add to this gap in the literature by analyzing how the effectiveness of transaction taxes depend on different behavioral patterns within an agent-based framework. Our simulations indicate that a tax rate of 0.1% demarcates the stabilizing tax regime from the destabilizing one. We figure out that transaction taxes are less effective, either when chartists trade more aggressively, fundamentalists trade less aggressively, agents switch more frequently between trading strategies or only have short memory in their fitness measures. Lower risk aversion of agents, however, makes higher tax rates more effective as indicated by a flatter volatility response curve. We conclude that additional regulations should concentrate on the traders’ responsibilities for their risk-exposure.     

Does a ‘financial transaction tax’ drive out information mirages? An experimental analysis

Motivated by the debate over the economic implications of financial transaction taxes, the present study involved a thorough investigation of the impact of such taxes on a financial market of the type described by Camerer and Weigelt (J Bus 64:463–493, 1991), whereby noise traders are unaware of whether privileged information is fluctuating in the market. Two treatment conditions were opposed to a baseline condition in which no tax was levied. The two treatment conditions imposed a transaction tax equal to 0.5% and 1% of each transaction’s market value, respectively. The findings show that: (1) the introduction of a tax did not affect the occurrence of a mirage, (2) the introduction of a tax did not improve market efficiency and (3) the introduction of a tax did not reduce the number of transactions.

     

Network structure,portfolio diversification and systemic risk

We investigate the effect of portfolio diversification on banking systemic risk, where the network effect is incorporated. We analyze three kinds of interbank networks, namely, random networks, small-world networks and scale-free networks. We show that the effect of portfolio diversification on banking systemic risk depends on interbank network structures and shock types. First, systemic risk increases first and then reduces with the increase of the level of portfolio diversification in the case of the individual shock. Second, in the case of the systemic shock, systemic risk reduces with the increases of the level of portfolio diversification. Third, banking systems with scale-free network structures are the most stable, and those with small-world network structures are the most vulnerable.     

Risk contagion in the banking network: New evidence from China

Based on data from 111 Chinese banks over the 2013–2016 period, this paper estimates the interbank bilateral lending matrix using the maximum entropy method. The estimated matrix is used to simulate the effects of credit and liquidity shocks on China’s banking network. Simulation results show that, under the extreme pressure scenario, the contagion arising from a liquidity shock is significantly stronger than the effect of a credit shock, indicating the importance of liquidity in the banking system. The contagion effect arising from a credit shock does not vary much over the sample period. However, the contagion effect arising from a liquidity shock decreases significantly, which could be attributed to contraction in interbank business due to stricter interbank business supervision. The simulation results also identify the most important and most vulnerable nodes of the banking system. An increase in the level of capital level can enhance the ability of banks to withstand credit and liquidity shocks. Our analysis also suggests that risk contagion faced by China’s banks varies across banking network structures.     

Understanding the consequences of diversification on financial stability

In this paper, we study the consequences of diversification on financial stability and social welfare using an agent based model that couples the real economy and a financial system. We validate the model against its ability to reproduce several stylized facts reported in real economies. We find that the risk of an isolated bank failure (i.e. idiosyncratic risk) is decreasing with diversification. In contrast, the probability of joint failures (i.e. systemic risk) is increasing with diversification which results in more downturns in the real sector. Additionally, we find that the system displays a “robust yet fragile” behaviour particularly for low diversification. Moreover, we study the impact of introducing preferential attachment into the lending relationships between banks and firms. Finally, we show that a regulatory policy that promotes bank–firm credit transactions that reduce similarity between banks can improve financial stability whilst permitting diversification.

     

Contagion risk in the Czech financial system: A network analysis and simulation approach

This paper examines the potential for contagion within the Czech banking system via the channel of interbank exposures of domestic banks, enriched by a liquidity channel and an asset price channel, over the period March 2007 to June 2012. A computational model is used to assess the resilience of the Czech banking system to interbank contagion, taking into account the size and structure of interbank exposures as well as balance sheet and regulatory characteristics of individual banks in the network. The simulation results suggest that the potential for contagion due to credit losses on interbank exposures was rather limited. Even after the introduction of a liquidity condition into the simulations, the average contagion was below 3.8% of the remaining banking sector assets, with the exception of the period from December 2007 to September 2008. Activation of the asset price channel further increases the losses due to interbank contagion, showing that the liquidity of government bonds would be essential for the stability of Czech banks in stress situations. Finally, the simulation results for both idiosyncratic and multiple bank failure shocks suggest that the potential for contagion in the Czech banking system has decreased since the onset of the global financial crisis.     

Interbank credit and the money manufacturing process: a systemic perspective on financial stability

Interbank lending and borrowing occur when financial institutions seek to settle and refinance their mutual positions over time and circumstances. This interactive process involves money creation at the aggregate level. Coordination mismatch on interbank credit may trigger systemic crises. This happened when, since summer 2007, interbank credit coordination did not longer work smoothly across financial institutions, eventually requiring exceptional monetary policies by central banks, and guarantee and bailout interventions by governments. Our article develops an interacting heterogeneous agent-based model of interbank credit coordination under minimal institutions. First, we explore the link between interbank credit coordination and the money generation process. Contrary to received wisdom, interbank credit has the capacity to remove the inner limits of monetary system capacitance. Second, we develop simulation analysis on imperfect interbank credit coordination, studying impact of interbank dynamics on financial stability and resilience at individual and aggregate levels. Systemically destabilizing forces prove to be related to the working of the banking system over time, especially interbank coordination conditions and circumstances.

     

Does the bank risk concentration freeze the interbank system?

Probably, one test of the stability of the banking system is to evaluate how risky assets are distributed across banks’ portfolios and the implications for the contagion via interbank relations. This paper explores theoretically a bank sector with risks concentration and the functioning of interbank markets. It employs a simple model where banks are exposed to both credit and liquidity risk that suddenly correlate over the business cycle. We show that risk concentration makes interbank market breakdowns more likely and welfare monotonically decreases in risk concentration.     

Networks and market-based measures of systemic risk: the European banking system in the aftermath of the financial crisis

This article investigates the behaviour of the European banking system during the financial crises that occurred in the last decades. Among the various approaches for measuring systemic risk, we consider network analysis, which describes the linkages among financial institutions and their whole structure. We construct a time-varying network of the European banking system. Banks are linked to form a global interconnected system and they mutually influence one another in terms of risk. We model their reciprocal influence via a weighted and directed network, in which weights are related to risk measures that are based on equity returns. Then, we apply two network indicators to investigate the prominence of a bank in spreading and receiving risk from the others. The results enable us to capture many features of the banking system while identifying the global systemically important banks. Moreover, the results of the analysis over time show how interconnections change over periods that are characterized by various economic scenarios.

     

An empirical study of the Mexican banking system’s network and its implications for systemic risk

With the aim to measure and monitor systemic risk, we present some topological metrics for the interbank exposures and the payments system networks. The evolution of such networks is analyzed, we draw important conclusions from the systemic risk's perspective and propose a measure of interconnectedness. Additionally, we suggest non-topological measures to describe individual behavior of banks in both networks. The main findings of this paper are: the structures of the payments and exposures networks are different (in terms of connectivity); the topology of the exposures network changed after the collapse of Lehman Brothers, whereas the structure of the payments network does not; the proposed measure of interconnectedness can be used to determine the importance of a bank in terms of connectivity. Finally, we found that interconnectedness of a bank is not necessarily related with its assets size but it is linked to the contagion it might cause.     

The default contagion of contingent convertible bonds in financial network

This paper investigates the impact of contingent convertible (CoCo) bonds on systemic risk using Eisenberg-Noe’s financial network method, in which the network is linked by debt relationships. As an efficient method for addressing the problem of “too big to fail,” CoCo bonds have received widespread attention, particularly because the trigger for CoCo bonds is a systemic risk event. Thus, the impact of CoCo bonds on systemic risk needs to be addressed. To solve this problem, we adopt default contagion and loss amplification due to network linkage to measure systemic risk, from which we can ascertain the potential impact on it of CoCo bonds. The results show that CoCo bonds enhance the spillover effect of the issuer’s default; meanwhile, sufficient CoCo bonds partly offset the impact of default contagion from other banks. Furthermore, CoCo bonds enhance the amplification effect of loss due to network linkage, but the amplification effect diminishes after the bankruptcy cost is considered. Finally, the numerical test provides some insight into how the issuance of writedown (WD) bonds influences commercial banks in China. Our study not only offers suggestions to the regulators of CoCo bonds but also contributes to related studies.     

A CRITICAL REVIEW OF CONTAGION RISK IN BANKING

The recent financial crisis has focused the attention of scholars and policymakers on how to improve financial stability through better macro‐prudential regulation and supervision. In this paper, we compare the existing theoretical and empirical literature on contagion through the banking system. It is argued that the structure of the interbank market, the size of banks, the linkages among them, the level of correlation of their investments and the transparency of the regulator are key factors in determining the possibility of contagion. We discuss the different findings and present avenues for future research.     

利率期限结构、商业银行投资组合与宏观经济波动——基于DSGE的分析框架

将包含同业业务的商业银行投资组合、利润和利率期限结构的局部均衡模型嵌入以家庭、资本投资者、商业银行、中间厂商和最终厂商为经济主体的DSGE模型中,分析商业银行风险错配、货币政策工具和经济增长对利率期限结构的影响。结果表明:经济增长冲击和商业银行的风险错配冲击对我国利率期限结构的影响最大,其次是数量型货币政策和价格型货币政策冲击。     

Robustness of banking networks to idiosyncratic and systemic shocks: a network-based approach

We propose a network-based structural model of credit risk to demonstrate how idiosyncratic and systemic shocks propagate across the banking system and evaluate the costs. The banking system is built as a network of heterogeneous banks which are connected with one another. In such a system, single credit events propagate through the interbank market from debtors to creditors and across the system. The shock is imposed as an unexpected event. We demonstrate that while idiosyncratic shocks cannot substantially disturb the banking system, a systemic shock of even a moderate magnitude can be highly detrimental. Such shock includes a huge contagious potential. We demonstrate that the costs of the shock are largely determined by the extent of contagion and range from negligible to catastrophic. The results imply that a severe crisis has to be initiated by a systemic shock of at least moderate magnitude. Capital ratio and the bank size are two additional factors of the banking system stability. Finally, credit risk analysis is sensitive to the network topology and exhibits a profound nonlinear characteristic.     

Shadow Banking,Chinese Style

Shadow banks are broadly defined as entities which conduct credit intermediation outside the formal banking system. Poorly regulated, engaging in opaque forms of intermediation, deeply interconnected with the official banking system, and operating with implicit government guarantees, they pose a major source of systemic risk. Yet shadow banks provide an important service by channeling credit to excluded investors, and can complement the formal banking sector. What explains the rapid proliferation of shadow banks in China? How large are they and what forms do they take? What types of risks do they pose to the financial system? And how best can China utilise the services of shadow banks while at the same time ensuring that they do not create systemic risks for the financial system?