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.     

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.     

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.     

Emergence of a core-periphery structure in a simple dynamic model of the interbank market

This paper studies a simple dynamic model of interbank credit relationships. Starting from a given balance sheet structure of a banking system with a realistic distribution of bank sizes, the necessity of establishing interbank credit connections emerges from idiosyncratic liquidity shocks. Banks initially choose potential trading partners randomly, but over time form preferential relationships via an elementary reinforcement learning algorithm. As it turns out, the dynamic evolution of this system displays a formation of a core-periphery structure with mainly the largest banks assuming the roles of money center banks mediating between the liquidity needs of many smaller banks. Statistical analysis shows that this evolving interbank market shares the majority of the salient characteristics of interbank credit relationship that have been put forth in recent literature. Preferential interest rates for borrowers with strong attachment to a lender may prevent the system from becoming extortionary and guarantee the survival of the small peripherical banks.     

Bank fee-based shocks and the U.S. business cycle

Efficient liquidity matching requires from banks to track external shocks (e.g., GDP growth shocks, stock market shocks and monetary policy shocks) in order to optimally allocate their assets between loans and other business lines. Profit maximizing banks have to rebalance their product-mix to take advantage of these changes. However, even though banking is cyclical, and contemporaneously reacts to shocks outside the banking sphere, there may also be some feedback effects at play, whereby bank changes, in turn, could affect economic and financial conditions. Generalizing the results of Marcucci and Quagliariello (2006, 2009), who indeed find an asymmetric impact of credit shocks on economic and financial time series in recession, we use a similar VAR framework to show that an even stronger feedback effect is prevalent for fee-based shocks. If the feedback effects of credit and fee-based shocks might have been both at play before the subprime crisis, the feedback effect of credit shocks seems to have faded away during the subprime crisis, whereas the feedback effect stemming from fee-based shocks has gained further strength.     

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.

     

There is no smoke without a fire: The effect of government interventions in less advanced economies

The lack of liquidity in the interbank market during the crisis of 2007–2011 led governments to impose different policies to rescue their countries’ banking sectors. While in advanced countries interventions in the banking sector were mostly related to a lack of liquidity and significant asymmetric information regarding counterparty risk, in many less advanced countries they had a precautionary motive. In our article, we investigate the effectiveness of policy interventions on healthy banking markets, with possible negative spill-over effects from other countries. To this extent, we use an event study methodology to test the effect of liquidity and financial sector policy announcements on interbank spread changes in six Central and Eastern European (CEE) countries over the period between 2007 and 2011. We find that standard liquidity interventions did not provide effective stabilization. In fact, our evidence suggests that the spread widened after their announcement, probably as a result of the negative signal and consequently increased risk aversion of banks. In such situations, regulators should consider policy instruments that aim to decrease uncertainty in the market.     

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.     

The federal funds market,excess reserves,and unconventional monetary policy

Following the bankruptcy of Lehman Brothers, interbank borrowing and lending dropped, whereas reserve holdings of depository institutions skyrocketed, as the Fed injected liquidity into the U.S. banking sector. This paper introduces bank liquidity risk and limited market participation into a real business cycle model with ex ante identical financial intermediaries and shows, in an analytically tractable way, how interbank trade and excess reserves emerge in general equilibrium. Investigating the role of the federal funds market and unconventional monetary policy for the propagation of aggregate real and financial shocks, I find that federal funds market participation is irrelevant in response to standard supply and demand shocks, whereas it matters for “uncertainty shocks”, i.e. mean-preserving spreads in the cross-section of liquidity risk. Liquidity injections by the central bank can absorb the effects of financial shocks on the real economy, although excess reserves might increase and federal funds might be crowded out, as a side effect.     

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.     

The role of banking regulation in an economy under credit risk and liquidity shock

This paper develops a Dynamic Stochastic General Equilibrium model which includes a financial sector to analyze the effects of liquidity shock and credit risk in the Brazilian economy. Banks use equity capital and deposits from agents to finance investments of the productive sector. The sources of financial frictions are default rate and liquidity shock, due to deposits withdrawn in advance. The banking supervisor injects liquidity in the deposit market. Using data for the Brazilian economy in the period from 1995 to 2009, the structural parameters are estimated by Bayesian methods. Impulse response functions are computed to describe the dynamic effects of exogenous shocks. The major results show that credit risk is pro-cyclical and default risk depends on structural features. The banking regulator is able to set up a policy to promote financial stability and efficiently reduce fluctuations in the output.     

Liquidity,bank runs,and fire sales under local thinking

We examine the implications on banking crises when markets are populated by agents that neglect tail risks and form expectations conditioned on a favorable subset of possible states of the economy. We find that optimal bank liquidity is lower than would be the case under rational expectations, and, consequently, the banking system is more vulnerable to adverse shocks, which lead to bank runs. Asset pledgeability of surviving banks is also affected so that their capacity to raise external funds for purchasing assets of distressed banks is weakened. Further, we examine the case when asset returns are correlated through securitization. In this case adverse shocks are felt uniformly across the banking sector and banks that survive with the help of a public liquidity backstop will become risk-averse and reluctant to purchase distressed assets. Finally, we explore a government funded asset purchase program, that is implemented with an asset price target.     

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.

     

Market microstructure,banks’ behaviour and interbank spreads: evidence after the crisis

We present a study of the European electronic interbank market of overnight lending (e-MID) before and after the beginning of the financial crisis. The main goal of the paper is to explain the structural changes of lending/borrowing features due to the liquidity turmoil. Unlike previous contributions that focused on banks’ dependent and macro information as explanatory variables, we address the role of banks’ behaviour and market microstructure as determinants of the credit spreads. We show that all banks experienced significant variations in their liquidity costs due to the sensitivity of interbank rates to the timing and side of trades. We argue that, while larger banks did experience better funding conditions after the crisis, this was not just a consequence of the “too big to fail” perception of the market. Larger banks have been able to play more strategically when managing their liquidity by taking advantage of the changing market microstructure.

     

A model of the topology of the bank – firm credit network and its role as channel of contagion

This paper proposes a stochastic model of a bipartite credit network between banks and the non-bank corporate sector that encapsulates basic stylized facts found in comprehensive data sets for bank-firm loans for a number of countries. When performing computational experiments with this model, we find that it shows a pronounced non-linear behavior under shocks: the default of a single unit will mostly have practically no knock-on effects, but might lead to an almost full-scale collapse of the entire system in a certain number of cases. The dependency of the overall outcome on firm characteristics like size or number of loans seems fuzzy. Distinguishing between contagion due to interbank credit and due to joint exposures to counterparty risk via loans to firms, the later channel appears more important for contagious spread of defaults.     

The granularity of the Brazilian banking market

Bank size distributions concentrate in a few large banks – the big “grains.” This fact means idiosyncratic shocks at the bank level do not cancel out, thus affecting the business cycle. Here, we present evidence of granularity in the banking market using Brazilian data. We examine the explanatory power of the granular banking residual of the five largest banks on quarterly GDP changes from 2010 to 2019. We conservatively find that shocks to revenues of these top five banks explain nearly one-fifth of GDP fluctuations.     

Financial stability of Islamic banking and the global financial crisis: Evidence from the Gulf Cooperation Council

Using a sample of 76 banks from the Gulf Cooperation Council region, we use accounting- as well as market-based measures of financial stability to examine whether Islamic banks outperformed conventional banks in the time of financial shocks during the period 2000–2013. We find that the difference between the two banking types was initially not significant during the GFC. However, when the financial shock spread to the real economy during the later phases of the crisis, Islamic banks suffered a significantly higher level of financial instability than conventional banks. This result holds true for large banks but not for small Islamic banks. Small Islamic banks demonstrated a relatively better handling of the economic downturn than large Islamic banks, supporting the argument that Islamic banks are more stable when they operate at a small scale but lose this stability when they increase their scale of operations. Hence, while Islamic banks may have escaped the consequences of highly volatile financial instruments, they were not spared from a major shock in the real economic sectors.     

The impact of funding liquidity on market quality

This study analyzes market quality during the 2007–2008 credit crunch, by examining the impact of funding liquidity on market liquidity and price discovery of S&P 500 exchange-traded funds (i.e., S&P 500 depositary receipts [SPYs]) and index futures (E-minis). The empirical results show that funding liquidity affects market liquidity, and that the impact of illiquidity contagion between SPYs and E-minis was significant during the subprime mortgage crisis. In particular, the contagion effects between the two markets mediate the impact of funding illiquidity on market liquidity during the credit crunch. Considering the influences of other market factors on price discovery, we suggest that E-mini index futures made less contributions to price discovery during the credit crunch compared to normal periods. The empirical finding emphasizes the importance of the contagion effect between ETF and E-mini futures markets, when they suffer from external shocks.     

The impact of credit supply shocks and a new Financial Conditions Index based on a FAVAR approach

This paper investigates the impact of credit supply shocks on the macroeconomy and estimates a new financial conditions index. We calculated two credit supply factors using a time-varying parameter FAVAR model. The first factor is identified as the willingness to lend, while the second factor is the lending capacity. The impact of these two types of shocks and their changes over time is examined using Hungarian data. The two types of lending shocks affect macro variables rather differently: a positive lending capacity shock (in a banking system mostly owned by non-residents) influences GDP through a decrease in country risk and the easing of monetary policy, while willingness to lend primarily increases lending activity. The two financial shocks also differ in terms of their evolution over time: deviations from the average in the impact of a willingness to lend shock usually occur for short periods of time and are of a small degree between the various quarters. However, in the case of lending capacity, certain trends can be observed: before the crisis, the stability of the banking system played an increasing role in country risk, whereas after 2008 it appears that monetary policy paid increasing attention to financial stability. Finally, a new type of financial conditions index is quantified based on our estimates, which measures the impact of the banking system’s lending activity on GDP growth.     

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.