Evaluating the impact of macroprudential policies on credit growth in Colombia

The purpose of this paper is to evaluate the effectiveness of two macroprudential policies in Colombia: marginal reserve requirements and dynamic provisions. The first measure was implemented to control excessive credit growth, while the latter was designed to increase systemic resilience by establishing a countercyclical buffer through loan loss provision requirements. To perform this analysis, a rich dataset based on loan-by-loan information for Colombian banks during the 2006–2009 period is used. Our identification strategy closely follows Khwaja & Mian (2008), so that only those observations with multiple banking relations are considered. Estimations are performed applying firm and firm-time fixed effects to control for demand factors, thus appropriately isolating loan demand from credit supply. Results from the econometric model suggest that dynamic provisions, the countercyclical reserve requirement and an aggregate measure of the macroprudential policy stance had a negative effect on credit growth, which varies according to bank and debtor-specific characteristics. Particularly, effects are intensified for riskier debtors, suggesting that the aggregate macroprudential policy stance in Colombia has worked effectively to stabilize credit cycles and reduce risk-taking.     

Systemic Bank Risk in Brazil: A Comprehensive Simulation of Correlated Market, Credit, Sovereign and Inter-Bank Risks

In this study we present a comprehensive forward‐looking portfolio simulation methodology for assessing the correlated impacts of market risk, private sector and Sovereign credit risk, and inter‐bank default risk. In order to produce better integrated risk assessment for banks and systemic risk assessments for financial systems, we argue that reasonably detailed modeling of bank asset and liability structures, loan portfolio credit quality, and loan concentrations by sector, region and type, as well as a number of financial and economic environment risk drivers, is required. Sovereign and inter‐bank default risks are increasingly important in the current economic environment and their inclusion is an important model extension. This extended model is demonstrated through an application to both individual Brazilian banks (i.e., 28 of the largest banks) and groups of banks (i.e., the Brazilian banking system) as of December 2004. When omitting Sovereign risk, our analysis indicates that none of the banks face significant default risk over a 1‐year horizon. This low default risk stems primarily from the large amount of government securities held by Brazilian banks, but also reflects the banks' adequate capitalizations and extraordinarily high interest rate spreads. We note that none of the banks which we modeled failed during the very stressful 2007‐2008 period, consistent with our results. Our results also show that a commonly used approach of aggregating all banks into one single bank, for purposes of undertaking a systemic banking system risk assessment, results in a misestimate of both the probability and the cost of systemic banking system failures. Once Sovereign risk is considered and losses in the market value of government securities reach 10% (or higher), we find that several banks could fail during the same time period. These results demonstrate the well known risk of concentrated lending to a borrower, or type of borrower, which has a non‐zero probability of default (e.g., the Government of Brazil). Our analysis also indicates that, in the event of a Sovereign default, the Government of Brazil would face constrained debt management alternatives. To the best of our knowledge no one else has put forward a systematic methodology for assessing bank asset, liability, loan portfolio structure and correlated market and credit (private sector, Sovereign, and inter‐bank) default risk for banks and banking systems. We conclude that such forward‐looking risk assessment methodologies for assessing multiple correlated risks, combined with the targeted collection of specific types of data on bank portfolios, have the potential to better quantify overall bank and banking system risk levels, which can assist bank management, bank regulators, Sovereigns, rating agencies, and investors to make better informed and proactive risk management and investment decisions.     

Credit Derivatives and the Default Risk of Large Complex Financial Institutions

This paper proposes and implements a multivariate model of the coevolution of the first and second moments of two broad credit default swap indices and the equity prices of sixteen large complex financial institutions. We use this empirical model to build a bank default risk model, in the vein of the classic Merton-type, which utilises a multi-equation framework to model forward-looking measures of market and credit risk using the credit default swap (CDS) index market as a measure of the conditions of the global credit environment. In the first step, we estimate the dynamic correlations and volatilities describing the evolution of the CDS indices and the banks’ equity prices and then impute the implied assets and their volatilities conditional on the evolution and volatility of equity. In the second step, we show that there is a substantial ‘asset shortfall’ and that substantial capital injections and/or asset insurance are required to restore the stability of our sample institutions to an acceptable level following large shocks to the aggregate level of credit risk in financial markets.     

Macroprudential policy transmission and interaction with fiscal and monetary policy in an emerging economy: a DSGE model for Brazil

We investigate the transmission of macroprudential (MaP) instruments in a dynamic stochastic general equilibrium model where foreign capital flows interact with financial frictions and banks are exposed to different sources of credit default risk. The model is estimated for Brazil with Bayesian techniques. We compute optimal combinations of simple MaP, fiscal and monetary policy rules that can react to the business and/or the financial cycle. We find that the gains from implementing a cyclical fiscal policy are only significant if MaP policy countercyclically reacts to the financial cycle. Optimal fiscal policy is countercyclical in the business cycle.     

Macroprudential stress testing of credit risk: A practical approach for policy makers

Drawing on the lessons from the global financial crisis and especially from its impact on the banking systems of Eastern Europe, the paper proposes a new practical approach to macroprudential stress testing. The proposed approach incorporates: (i) macroeconomic stress scenarios generated from both a country specific statistical model and historical cross-country crises experience; (ii) indirect credit risk due to foreign currency exposures of unhedged borrowers; (iii) varying underwriting practices across banks and their asset classes based on their relative aggressiveness of lending; (iv) higher correlations between the probability of default and the loss given default during stress periods; (v) a negative effect of lending concentration and residual loan maturity on unexpected losses; and (vi) the use of an economic risk weighted capital adequacy ratio as the relevant outcome indicator to measure the resilience of banks to materializing credit risk. The authors apply the proposed approach to a set of Eastern European banks and discuss the results.     

An integrated macroprudential stress test of bank liquidity and solvency

We propose a new measure of systemic financial distress that incorporates idiosyncratic and systemic risks in the financial system network. Using this measure, we develop an integrated stress test of bank liquidity and solvency risks based on the dynamics of financial distress within the banking system network. We apply this stress test framework to the US banking system and identify systemic vulnerability of individual banks as well as the resilience of the system as a whole to an economic shock. The framework helps us identify and monitor systemic interdependencies between banks. The proposed stress testing framework is useful for practical macroprudential monitoring and is informative for policy making.     

Systemic risk in the European sovereign and banking system

We investigate the systemic risk of the European sovereign and banking system during 2008–2013. We utilize a conditional measure of systemic risk that reflects market perceptions and can be intuitively interpreted as an entity’s conditional joint probability of default, given the hypothetical default of other entities. The measure of systemic risk is applicable to high dimensions and not only incorporates individual default risk characteristics but also captures the underlying interdependent relations between sovereigns and banks in a multivariate setting. In empirical applications, our results reveal significant time variation in systemic risk spillover effects for the sovereign and banking system. We find that systemic risk is mainly driven by risk premiums coupled with a steady increase in physical default risk.     

Optimal macroprudential policy and rational bubbles

We provide a microfounded framework for the welfare analysis of macroprudential policy within a model of rational bubbles. For this, we posit an overlapping generation model where productivity and credit supply are subject to random shocks. We find that when real interest rates are lower than the rate of growth, credit financed bubbles may be welfare improving because of their role as a buffer in channeling excessive credit supply and inefficient investment at the firms’ level, but their sudden price decrease may cause a systemic crisis. Therefore, a well designed macroprudential policy plays a key role in improving efficiency while preserving financial stability. Our theoretical framework allows us to compare the efficiency of alternative macroprudential policies. Contrarily to conventional wisdom, we show that macroprudential policy (i) may be efficient even in the absence of systemic risk, (ii) has to be contingent on productivity shocks and (iii) must be contingent upon the level of real interest rates.     

对货币政策和宏观审慎政策双支柱调控框架内在逻辑的思考

本轮国际金融危机以来,金融稳定在中央银行政策目标中的重要性再次得到强化。随着具有顺周期波动特征的金融市场和金融资产规模显著增大,金融管理政策需要更加关注金融稳定和系统性风险问题,货币稳定和金融稳定“双目标”的重要性凸显出来。政策目标的变化相应要求优化和完善政策工具箱,需要健全宏观审慎政策框架作为应对系统性风险的工具,并与货币政策相互配合,形成由货币政策和宏观审慎政策“双支柱”支撑起“双目标”的基本框架,共同维护好货币稳定和金融稳定。在此框架中,货币政策和宏观审慎政策都不可或缺,须相互补充,形成合力,产生“一加一大于二”的政策效应增进效果。健全货币政策和宏观审慎政策双支柱调控框架,有利于把经济周期和金融周期更好地结合起来,把维护经济稳定与促进金融稳定更好地结合起来。下一阶段应进一步健全宏观审慎政策框架,并完善货币政策和宏观审慎政策协调配合的体制机制。     

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.     

M‐PRESS‐CreditRisk: Microprudential and Macroprudential Capital Requirements for Credit Risk under Systemic Stress

M‐PRESS‐CreditRisk is a novel stress testing approach that can help authorities gauge banks' capital adequacy related to credit risk. For the first time, it combines the assessment of microprudential capital requirements under Pillars 1 and 2 and macroprudential buffers in a unified, coherent framework. Its core element is an advanced credit portfolio model—SystemicCreditRisk—built upon a rich, nonlinear dependence structure for correlated bank portfolios. The model is applied to a sample of 12 systemically important German banking groups and delivers measures for systemic credit risk and the banks' contributions to it in both baseline and stress scenarios.     

The impact of macroprudential policies in Latin America: An empirical analysis using credit registry data

This paper summarises the results of a joint research project by five central banks in Latin America countries (Argentina, Brazil, Colombia, Mexico and Peru) to evaluate the effectiveness of macroprudential tools and their interaction with monetary policy. Using meta-analysis techniques, we summarise the results of a common empirical framework based on confidential bank-loan data. The main conclusions are that (i) macroprudential policies have been quite effective in stabilising credit cycles. The propagation of the effects to credit growth is more rapid for policies aimed at curbing the cycle than for policies aimed at fostering resilience; and (ii) macroprudential tools have a greater effect on credit growth when reinforced by the use of monetary policy.     

Euro area banking and monetary policy shocks in the QE era

This paper assesses the effects of monetary policy shocks on the macroeconomy and the euro area banking sector after the global financial crisis. First, financial risk-return indicators of the banking sector based on a compound option-based structural credit risk model are embedded in a large macro-financial quarterly database covering the period 2008Q4–2019Q4. Second, a SFAVAR identifies and estimates the shocks’ responses relating them to the endogenous build-up of banks’ vulnerabilities which are consistent with the internally coherent structure of the credit risk model. By introducing structure in the understanding of banks’ asset-liability management behavior following monetary policy shocks, the research strategy contributes to disentangling results that are often mixed in the empirical literature. The study finds that unconventional monetary policy, in particular the Asset Purchase Program of the European Central Bank, seems to have been more successful than conventional monetary policy in raising output and inflation. The desired boost to bank lending has been muted and loan cyclicality has varied across countries and loan types. The performance of the banking sector following monetary policy shocks can be characterized by a drop in expected return on equity and assets, a relaxation of lending conditions and increased correlation between banks’ assets return and the market return, a mechanism pointing to enhanced risk-taking. While banks’ probabilities of default fall following monetary policy shocks, the price of risk increases. Banks’ net worth rises via higher market capitalization and implied assets value together with lower volatility, despite often incurring more debt. Risk-taking in the banking sector may pose a risk to financial stability, especially if its effects on banks’ vulnerability spread and increase systemic risk. The unintended endogenous build-up of macro-financial vulnerabilities may need to become part of monetary policymaking.     

基于动态因子Copula模型的我国银行系统性风险度量

本文基于2007年至2019年我国14家上市银行的股票收益率,构建偏态t-分布动态因子Copula模型,利用时变荷载因子刻画单家银行与整个系统的相关性,计算联合风险概率作为系统性风险整体水平的度量,基于关联性视角提出了新的单家机构系统脆弱性和系统重要性度量指标——系统脆弱性程度和系统重要性程度。该方法充分考虑了银行个体差异性和系统的内在关联性以及收益率的厚尾性和非对称性,从而能够捕捉到更多的信息且兼具时效性。研究表明:银行机构在风险聚集时期相关程度更大,联合风险概率能够准确识别出系统性风险事件且在我国推行宏观审慎评估体系以后有明显降低;整体而言,大型商业银行系统重要性水平最高,同时风险抗压能力也最强;本文使用的度量方法降低了数据获取成本且更具时效性,有助于为宏观审慎差异化监管工作提供借鉴和参考。     

Global systemic risk measures and their forecasting power for systemic events

Since the financial crisis of 2007–2009, many market-based systemic risk measures have been proposed. Prominent examples are MES, SRISK or ΔCoVaR. Based on a simulation study in an extended banking network model that incorporates several sources of systemic risk, we analyze how well these systemic risk measures perform in indicating the risk of a systemic event. For this analysis, the systemic risk measures of the banks that default and whose default is followed by a systemic event are compared with the systemic risk measures of those defaulting banks for which no subsequent systemic event can be observed. Within the simulation study, we find that many bank-individual systemic risk measures are statistically significant in explaining the likelihood of a systemic event after a bank’s default. However, the economic significance of the bank-individual systemic risk measures is relatively low.     

Concentrated commonalities and systemic risk in China's banking system: A contagion network approach

China's banking system has seen increasing convergence in exposures to different asset types. These concentrated commonalities have far reaching implications on systemic financial risk. Based on the commonality structure of banks' balance sheets, we construct a bipartite financial network and design novel indicators to analyze the systemic risk of China's banking system and its relation to the real economy. Results show that (1) considering the interconnectivity, indirect loss arising from common exposure is much higher than direct loss; (2) concentrated common exposure to mortgage is demonstrated to be the most significant source of systemic vulnerability in China; (3) the derived contagion network shows the property of “small world”, which plays an important role in generating systemic risk, amplified non-linearly by multi-rounds of contagion; (4) a bank's systemic importance/vulnerability depends on complex interaction between asset volume, leverage rate, and its commonality of asset composition to other banks. The model proposed in this study provides a new structural perspective to investigate the systemic risk, and a macroprudential instrument to complement existing stress testing that contributes to more efficient and precise regulations. Moreover, we contribute a ranking framework to assess each bank's systemic importance as well as vulnerability corresponding to specific real sectors.     

Dynamical macroprudential stress testing using network theory

The increasing frequency and scope of financial crises have made global financial stability one of the major concerns of economic policy and decision makers. This has led to the understanding that financial and banking supervision has to be thought of as a systemic task, focusing on the interdependent relations among the institutions. Using network theory, we develop a dynamic model that uses a bipartite network of banks and their assets to analyze the system’s sensitivity to external shocks in individual asset classes and to evaluate the presence of features underlying the system that could lead to contagion. As a case study, we apply the model to stress test the Venezuelan banking system from 1998 to 2013. The introduced model was able to capture monthly changes in the structure of the system and the sensitivity of bank portfolios to different external shock scenarios and to identify systemic vulnerabilities and their time evolution. The model provides new tools for policy makers and supervision agencies to use for macroprudential dynamical stress testing.     

Assessing systemic risk using interbank exposures in the global banking system

This paper contributes to the literature on systemic risk by examining the network structure of bilateral exposures in the global banking system. The global interbank market constitutes a major part of the global banking system. The market has a hierarchical network structure, composed of the national or jurisdictional area's local markets and the cross-border interbank market. First, we estimate the bilateral exposures matrix using aggregate financial data on loans and deposits from Bankscope and analyze the interconnectedness in the market using network centrality measures. Subsequently, for the model analysis, we apply the Eisenberg–Noe framework to a multi-period setting. In this framework, bank defaults are classified into stand-alone defaults and contagious defaults. The banks in our sample (i.e., the top 202 banks with more than $50 billion in total assets) comprise a major part of this global banking system. The main findings are as follows: The theoretical network analysis using network centrality measures showed that most of the banks designated as global systemically important banks (G-SIBs) play a central role in the global interbank market. The theoretical default analysis showed a few contagious defaults triggered by the basic defaults during and after the global financial crisis. Our stress test proved that many G-SIBs theoretically caused 1–6 contagious defaults. Our methodology would assist in the development of a monitoring system by the respective supervisory authorities as well as in the implementation of bank-internal stress tests of default contagion.     

The credit quality channel: Modeling contagion in the interbank market

We propose an algorithm to model contagion in the interbank market via what we term the “credit quality channel”. In existing models on contagion via interbank credit, external shocks to banks often spread to other banks only in case of a default. In contrast, shocks are transmitted also via asset devaluations and deteriorations in the credit quality in our algorithm. First, the probability of default (PD) of those banks directly affected by some shock increases. This increases the expected loss of the credit portfolios of the initially affected banks’ counterparties, thereby reducing the counterparties’ regulatory capital ratio. From a logistic regression we estimate the increase in the counterparties’ PD due to a reduced capital ratio. Their increased PDs in turn affect the counterparties’ counterparties, and so on. This coherent and flexible framework is applied to the bilateral interbank credit exposure of the entire German banking system in order to examine policy questions. For that purpose, we propose to measure the potential cost of contagion of a given shock scenario by the aggregated regulatory capital loss computed in our algorithm.     

基于动态因子Copula模型的我国银行系统性风险度量

本文基于2007年至2019年我国14家上市银行的股票收益率,构建偏态t-分布动态因子Copula模型,利用时变荷载因子刻画单家银行与整个系统的相关性,计算联合风险概率作为系统性风险整体水平的度量,基于关联性视角提出了新的单家机构系统脆弱性和系统重要性度量指标——系统脆弱性程度和系统重要性程度。该方法充分考虑了银行个体差异性和系统的内在关联性以及收益率的厚尾性和非对称性,从而能够捕捉到更多的信息且兼具时效性。研究表明:银行机构在风险聚集时期相关程度更大,联合风险概率能够准确识别出系统性风险事件且在我国推行宏观审慎评估体系以后有明显降低;整体而言,大型商业银行系统重要性水平最高,同时风险抗压能力也最强;本文使用的度量方法降低了数据获取成本且更具时效性,有助于为宏观审慎差异化监管工作提供借鉴和参考。