Financial Fragility and Interacting Units: an Exercise
This paper assumes that financial fluctuations are the result of the dynamic interaction between liquidity and solvency conditions of individual financial units. The framework is designed as a heterogeneous agent model which proceeds through discrete time steps within a finite time horizon. The interaction at the microlevel between financial units and the market maker, who is in charge of clearing the market, produces interesting complex dynamics. The model is analyzed by means of numerical simulations and agent-based computational economics (ACE) approach. The behaviour and evolution of financial units are studied for different parameter regimes in order to show the importance of the param…
Multi-Agent Financial Network (MAFN) Model of US Collateralized Debt Obligations (CDO)
A database driven multi-agent model has been developed with automated access to US bank level FDIC Call Reports that yield data on balance sheet and off balance sheet activity, respectively, in Residential Mortgage Backed Securities (RMBS) and Credit Default Swaps (CDS). The simultaneous accumulation of RMBS assets on US banks' balance sheets and also large counterparty exposures from CDS positions characterized the $2 trillion Collateralized Debt Obligation (CDO) market. The latter imploded at the end of 2007 with large scale systemic risk consequences. Based on US FDIC bank data, that could have been available to the regulator at the time, the authors investigate how a CDS negative carry …
The Cyclicality of Bank Credit Losses and Capital Ratios under Expected Loss Model
We model the evolution of stylised bank loan portfolios to assess the impact of IFRS 9 and US GAAP expected loss model (ECL) on the cyclicality of loan loss provisions (LLPs), realised losses and capital ratios of banks, relative to the incurred loss model of IAS 39. We focus on the interaction between the changes in LLPs charges (the flow channel) and stocks (the stock channel) under ECL. Our results show that, when GDP growth doesn’t demonstrate high volatility, ECL model smooths the impact of credit losses on profits and capital resources, reducing the pro-cyclicality of capital and leverage ratios, especially under US GAAP. However, when GDP growth is highly volatile, the large differen…
The grass is always greener on the other side of the fence: the effect of misperceived signalling in a network formation process
Social and economic networks are becoming increasingly popular in the last ten years, because of both the application of game theory to the network formation processes4, and the study of stochastic processes that fit the statistical properties of real world social networks.5 In the very recent years there have also been attempts to combine the contribution of these two streams of research, trying to find strategic models whose equilibria resemble the empirical data.6 A well known source of debate in the game theoretical approach is the incompatibility between stability and efficiency: in most of the models Nash equilibria are actually not the network architectures that maximize the overall …
Economic Support during the COVID Crisis. Quantitative Easing and Lending Support Schemes in the UK
Abstract We investigate how UK bank business lending responded to the simultaneous use of quantitative easing, leverage ratio capital requirements, and government COVID lending support schemes. We find no evidence that the Brexit wave increased lending to nonfinancial businesses, compared to the previous waves, except for QE-banks subject to the UK leverage ratio, suggesting that the ratio incentivised QE-banks to lend to businesses. The government schemes helped expand lending especially to SMEs post the COVID wave, indicating that complementing QE with other credit easing programmes can reinforce its impact on lending to the real economy. During COVID-stress, changes to the UK leverage ra…
Interbank lending and the spread of bank failures: A network model of systemic risk
We model a stylized banking system where banks are characterized by the amount of capital, cash reserves and their exposure to the interbank loan market as borrowers as well as lenders. A network of interbank lending is established that is used as a transmission mechanism for the failure of banks through the system. We trigger a potential banking crisis by exogenously failing a bank and investigate the spread of this failure within the banking system. We find the obvious result that the size of the bank initially failing is the dominant factor whether contagion occurs, but for the extent of its spread the characteristics of the network of interbank loans are most important. These results ha…
The asset reallocation channel of quantitative easing. The case of the UK
We investigate the impact of the Bank of England's asset purchase program (APP) on the composition of assets of UK banks with unique data on the received reserves injections. The Monetary Policy Committee (MPC) didn't expect there to be strong transmission of the APP's impact through the bank lending channel. We find that compared to the control group, treated banks reallocated their assets towards lower risk-weighted investments, such as government se-curities, but did not provide more credit to the real economy. Overall, our findings suggest that when banks are not adequately capitalised, risk-based capital constraints can limit the effec-tiveness of expansionary unconventional monetary p…
Carbon Emissions Announcements and Market Returns
The paper investigates the impact of carbon emissions on stock price returns of European listed firms. This relationship is assessed across all three emissions scopes, as well as using expecta-tions to detect if future emissions impact contemporary returns. Our findings show that firms with higher expected future emissions deliver contemporary lower returns, after controlling for market capitalization, profit, and other known return predictors. This result is statistically sig-nificant in the post Paris Agreement period with a two to three years expectation on scope 2 emissions. However, there is marginal to no significant negative relationship between current emissions and current returns.…
Network-Based Computational Techniques to Determine the Risk Drivers of Bank Failures During a Systemic Banking Crisis
This paper employs a computational model of solvency and liquidity contagion assessing the vulnerability of banks to systemic risk. We find that the main risk drivers relate to the financial connections a bank has and the market concentration, apart from the size of the bank triggering the contagion, while balance sheets play only a minor role. We also find that market concentration might facilitate banks to withstand liquidity shocks better while exposing them to larger solvency chocks. Our results are validated through an out-of-sample forecasting that shows that both type I and type II prediction errors are reduced if we include network characteristics in our prediction model.
Early warning of systemic risk in global banking: eigen-pair R number for financial contagion and market price-based methods
AbstractWe analyse systemic risk in the core global banking system using a new network-based spectral eigen-pair method, which treats network failure as a dynamical system stability problem. This is compared with market price-based Systemic Risk Indexes (SRIs), viz. Marginal Expected Shortfall (MES), Delta Conditional Value-at-Risk (Delta-CoVaR), and Conditional Capital Shortfall Measure of Systemic Risk (SRISK) in a cross-border setting. Unlike paradoxical market price based risk measures, which underestimate risk during periods of asset price booms, the eigen-pair method based on bilateral balance sheet data gives early-warning of instability in terms of the tipping point that is analogou…
A systemic risk assessment of OTC derivatives reforms and skin‑in‑the‑game for CCPs
The G20 OTC (over-the-counter) derivatives reforms impose large collateral/liquidity demands on clearing members of Central Counterparty (CCP) clearing platforms in the form of initial margins, variation margins and contributions to the default fund. In Heath et al. (2016), it was shown how this introduces a trade-off between liquidity risk and solvency risk with the system manifesting considerable systemic risk from these two sources of risk while CCP penetration is at current levels. The authors extend this analysis to include the European Market Infrastructure Regulation (EMIR) skin-in-the-game requirements for CCPs, which aim to ameliorate the contributions to the default fund by cleari…
Marginal contribution, reciprocity and equity in segregated groups: Bounded rationality and selforganization in social networks
We study the formation of social networks that are based on local interaction and simple rule following. Agents evaluate the profitability of link formation on the basis of the Myerson-Shapley principle that payoffs come from the marginal contribution they make to coalitions. The NP-hard problem associated with the Myerson-Shapley value is replaced by a boundedly rational 'spatially' myopic process. Agents consider payoffs from direct links with their neighbours (level 1), which can include indirect payoffs from neighbours' neighbours (level 2) and up to M-levels that are far from global. Agents dynamically break away from the neighbour to whom they make the least marginal contribution. Com…
Fair immunization and network topology of complex financial ecosystems
The aftermath of the recent financial crisis has shown how expensive and unfair the stabilization of financial ecosystems can be. The main cause is the level of complexity of financial interactions that poses a problem for regulators. We provide an analytical framework that decomposes complex ecosystems in both their overall level of instability and the contribution of institutions to instability. These ingredients are then used to study the pathways of the ecosystems towards stability by means of immunization schemes. The latter can be designed to penalize institutions proportionally to their contribution to instability, and therefore enhance fairness. We show that fair immunization scheme…
The impact of quantitative easing on UK bank lending: Why banks do not lend to businesses?
Abstract The growing proportion of UK bank lending to the financial sector reached a peak in 2007 just before the onset of the Global Financial Crisis (GFC). This marks a trend in the dwindling amount of bank lending to private sector non-financial corporations (PNFCs), which was exacerbated with the Great Recession. Many central banks aimed to revive bank lending with quantitative easing (QE) and unconventional monetary policy. We propose an agent based computational economics (ACE) model which combines the main factors in the economic environment of QE and Basel regulatory framework to analyse why UK banks do not prioritize lending to non-financial businesses. The lower bond yields caused…
Banks’ business strategies on the edge of distress
AbstractThe paper investigates the importance of banks’ business classification in shaping the risk profile of financial institutions on a global scale. We employ a rare-event logit model based on a state-of-the-art list of major global distress events from the global financial crisis. When clustering banks by their business strategies using a community detection approach, we show that (i) capital enhanced resilience only for traditional banks that were on average less capitalized than other banks; (ii) boosting ROE, usually associated with riskier exposures, improved resilience for stable funded and asset diversified banks; (iii) conversely, higher levels of ROA exacerbated banks’ vulnerab…
Multi-Agent Financial Network (MAFN) Model of US Collateralized Debt Obligations (CDO)
A database driven multi-agent model has been developed with automated access to US bank level FDIC Call Reports that yield data on balance sheet and off balance sheet activity, respectively, in Residential Mortgage Backed Securities (RMBS) and Credit Default Swaps (CDS). The simultaneous accumulation of RMBS assets on US banks’ balance sheets and also large counterparty exposures from CDS positions characterized the $2 trillion Collateralized Debt Obligation (CDO) market. The latter imploded at the end of 2007 with large scale systemic risk consequences. Based on US FDIC bank data, that could have been available to the regulator at the time, the authors investigate how a CDS negative carry …
Liquidity Costs and Tiering in Large-Value Payment Systems
This paper develops and simulates a model of the emergence of networks in an interbank, RTGS payment system. A number of banks, faced with random streams of payment orders, choose whether to link directly to the payment system, or to use a correspondent bank. Settling payments directly on the system imposes liquidity costs which depend on the maximum liquidity overdraft incurred during the day. On the other hand, using a correspondent entails paying a flat fee, charged by the correspondent to recoup liquidity costs and to extract a profit. We specify a protocol whereby one bank in each period can revisit its choice whether to link directly to the system, or to become clients of other banks,…
Structural contagion and vulnerability to unexpected liquidity shortfalls
This paper assumes that financial fluctuations are the result of the dynamic interaction between liquidity and solvency conditions of individual economic units. The framework is an extention of Sordi and Vercelli (2012) designed as an heterogeneous agent model which proceeds through discrete time steps within a finite time horizon. The interaction at the micro-level between economic units monitors the spread of contagion and systemic risk, producing interesting complex dynamics. The model is analysed by means of numerical simulations and systemic risk modelling, where local interaction of units is captured and analysed by the bilateral provision of liquidity among units. The behaviour and e…
‘Too interconnected to fail’ financial network of US CDS market: Topological fragility and systemic risk
A small segment of credit default swaps (CDS) on residential mortgage backed securities (RMBS) stand implicated in the 2007 financial crisis. The dominance of a few big players in the chains of insurance and reinsurance for CDS credit risk mitigation for banks' assets has led to the idea of too interconnected to fail (TITF) resulting, as in the case of AIG, of a tax payer bailout. We provide an empirical reconstruction of the US CDS network based on the FDIC Call Reports for off balance sheet bank data for the 4th quarter in 2007 and 2008. The propagation of financial contagion in networks with dense clustering which reflects high concentration or localization of exposures between few parti…