Measuring Credit Risk of a Bank's Corporate Loan Portfolio Using Advanced Internal Ratings Base Approach

Abstract

The use of technical and advanced approaches in the measurement of credit risk of banks' portfolios has nowadays become a very hot issue. The most recent technical report issued by the Basel Committee in May 2003 has concentrated heavily on the measurement of credit risk using either foundation or advanced Internal Ratings Base (IRB) approaches. This empirical research study attempts to measure credit risk of a bank's corporate loan portfolio, including firms from 10 different Turkish sectors. The monthly observations of the total amount of corporate loans and the total amount of corporate loans at default across various sectors are downloaded from the web page of Central Bank of Turkey (CBT) in a period of 1999-2002. This period covers 47 monthly observations since CBT has captured sectoral corporate loans beginning of 1999. Therefore, the observed sectoral default rates are needed to be simulated to obtain a nicely shaped distribution. Monte Carlo simulation is applied for 1,000 times. Based on the simulated default rates, the expected sectoral default rates are computed. Next, a credit quality rating scale is fitted into sectoral default rates distributions. Finally, the sectoral weights in the whole loan portfolio are multiplied by the expected sectoral default rates matrix, considering cross-sectoral correlations to get the total amount of the bank's credit risk and capital requirement. It is assumed that sectoral monthly default rates are a good representative of the default risk of a sample bank's corporate loan portfolio since no publicly available data on any particular bank's corporate loan portfolio composition exists. Nevertheless, this research may be a good application for measuring the credit risk of banks' corporate loan portfolios using advanced IRB approach.     

Forecasting and decomposition of portfolio credit risk using macroeconomic and frailty factors

This paper presents a dynamic portfolio credit model following the regulatory framework, using macroeconomic and latent risk factors to predict the aggregate loan portfolio loss in a banking system. The latent risk factors have three levels: global across the entire banking system, parent-sectoral for the intermediate loan sectors and sector-specific for the individual loan sectors. The aggregate credit loss distribution of the banking system over a risk horizon is generated by Monte Carlo simulation, and a quantile estimator is used to produce the aggregate risk measure and economic capital. The risk contributions of the individual sectors and risk factors are measured by combining the Hoeffding decomposition with the Euler capital allocation rule. For the U.S. banking system, we find that the real GDP growth rate, the global and sector-wide frailty risk factors and their spillovers significantly affect loan defaults, and the impacts of the frailty factors are not only economy-wide but also sector-specific. We also find that the frailty risk factors make more significant risk contributions to the aggregate portfolio risk than the macroeconomic factors, while the macroeconomic factors help to improve the accuracy and efficiency of the credit risk forecasts.     

Gender analysis of entrepreneurial intentions as a function of economic development across three groups of countries

The aim of this paper is to analyze the gender differences in entrepreneurial intentions by studying a range of socioeconomic and psychosocial factors. Furthermore, we aim at analyzing these differences in three groups of countries depending on the stage of economic development of each country according to the Global Competitiveness Report. Using a logistic regression analysis and data from the 2008 APS (Adult Population Survey) database which is part of the Project GEM (Global Entrepreneurship Monitor), results show the existence of gender differences in entrepreneurial intentions. The model proposed in the study has decreasing explanatory power as the degree of economic development increases, and is also more conclusive for men than women. An important methodological innovation we implemented in the current study is the use of the variable gender as a dependent variable rather than a variable of a socio demographic nature.     

A through-the-cycle model for retail lending economic capital

Problems in the US mortgage industry have shown weaknesses in the standard regulatory and economic capital approaches. Although a significant amount of discussion is occurring around how to segment portfolios or predict key variables in order to better fit the existing formulas, we believe that a re-examination of existing capital formulas with respect to credit risk is required.In this paper we develop a formula which is specifically tuned to the dynamics of retail loan portfolios and which could be employed for either regulatory capital or economic capital. The key advantages of this approach are that it is based upon a much more accurate model of retail loan defaults, does not require any new data feeds, is based upon readily available modeling frameworks, and can adapt to portfolio changes such as those observed in the US mortgage crisis.     

Portfolio optimization based on GARCH-EVT-Copula forecasting models

This study uses GARCH-EVT-copula and ARMA-GARCH-EVT-copula models to perform out-of-sample forecasts and simulate one-day-ahead returns for ten stock indexes. We construct optimal portfolios based on the global minimum variance (GMV), minimum conditional value-at-risk (Min-CVaR) and certainty equivalence tangency (CET) criteria, and model the dependence structure between stock market returns by employing elliptical (Student-$t$ and Gaussian) and Archimedean (Clayton, Frank and Gumbel) copulas. We analyze the performances of 288 risk modeling portfolio strategies using out-of-sample back-testing. Our main finding is that the CET portfolio, based on ARMA-GARCH-EVT-copula forecasts, outperforms the benchmark portfolio based on historical returns. The regression analyses show that GARCH-EVT forecasting models, which use Gaussian or Student-$t$ copulas, are best at reducing the portfolio risk.     

基于BAPM的企业权益资本成本研究

在行为资产定价模型（BAPM）,股票的权益资本成本和行为β相关。在非有效市场中,无风险利率、市场投资组合、行为β和市场风险溢价共同决定了权益资本成本。     

Intertemporal consumption choices,transaction costs and limited participation in financial markets: reconciling data and theory

This paper builds a unifying framework based on the theory of intertemporal consumption choices that brings together the limited participation‐based explanation of the Consumption Capital Asset Pricing Model's poor empirical performance and the transaction costs‐based explanation of incomplete portfolios. Using the implications of the consumption model and observed household consumption and portfolio choices, we identify the preference parameters of interest and a lower bound for the costs rationalizing non‐participation in financial markets. Using the US Consumer Expenditure Survey and assuming isoelastic preferences, we estimate the coefficient of relative risk aversion at 1.7 and a cost bound of 0.4% of non‐durable consumption. Our estimate of the preference parameter is theoretically plausible and the bound sufficiently small to be likely to be exceeded by the actual total (observable and unobservable) costs of participating in financial markets. Copyright © 2010 John Wiley & Sons, Ltd.     

Default estimation,correlated defaults,and expert information

Capital allocation decisions are made on the basis of an assessment of creditworthiness. Default is a rare event for most segments of a bank's portfolio and data information can be minimal. Inference about default rates is essential for efficient capital allocation, for risk management and for compliance with the requirements of the Basel II rules on capital standards for banks. Expert information is crucial in inference about defaults. A Bayesian approach is proposed and illustrated using prior distributions assessed from industry experts. A maximum entropy approach is used to represent expert information. The binomial model, most common in applications, is extended to allow correlated defaults yet remain consistent with Basel II. The application shows that probabilistic information can be elicited from experts and econometric methods can be useful even when data information is sparse. Copyright © 2009 John Wiley & Sons, Ltd.     

AIDS in the workplace: Options and responsibilities

Scientists now believe that no one is safe from AIDS. AIDS is no longer “the disease” of a small fringe segment of society. It is now a disease that can touch us in our personal, family, and professional lives. AIDS is, as columnist Ellen Goodman has suggested, an “equal opportunity infector” that does not discriminate on the basis of race, age, sex, or sexual orientation. Although statistics indicate that most of us will probably not experience AIDS in our private or family lives, a significant number of us will be forced to grapple with AIDS in the workplace. This article is an attempt to examine the business community's response to AIDS, and the possible options and strategies that larger corporations especially might use in responding to the medical, legal, and ethical dimensions of the disease. According to Nancy L. Merritt, vice-president and director of equal opportunity for Bank of America, AIDS raises at least three fundamental issues in the workplace: How do you handle an employee with AIDS? How do you educate and ensure the safety and morale of your other employees? How do you balance the needs of business with the human, ethical considerations raised by the disease? Such questions, Merritt maintains, will become more and more pressing as the AIDS epidemic continues to spread.     

Bank failure,risk, and capital regulation

This paper examines the effect of capital regulation on bank risk. It is shown that an increase in the capital-to-asset ratio reduces the riskiness of a bank's equity capital. Nevertheless, the probability of bank failure increases. The reason for this result is that the probability of bank failure depends upon both the risk and return of the asset portfolio. An increase in the capital requirement results in an optimal portfolio with a risk-return combination that has a higher probability of bank failure.     

农地“三权分置”改革对农业内生发展的影响机制及实证检验

农地"三权分置"改革通过影响农业资本、技术、劳动力等生产投入要素进而影响农业内生发展。本文利用调研数据对其实证检验的结果表明,代表农地"三权分置"改革的土地确权和土地转入显著提高了农户的农业投资及贷款意愿,提升了其农业科技使用意愿,并增强了其农业人力资本提升意愿;而代表"三权分置"改革的土地转出对三者的影响均为负。由此表明,农地"三权分置"改革对农业资本、技术和劳动力的内生增长有显著促进作用,进而推动农业内生发展。建议深化"三权分置"改革,推进确权成果应用,完善土地流转机制,借助大数据建立网络化土地流转平台,以土地为杠杆撬动农业其他生产要素投入。     

Reaching nirvana with a defaultable asset?

We study the optimal dynamic portfolio exposure to predictable default risk, taking inspiration from the search for yield by means of defaultable assets observed before the 2007–2008 crisis and in its aftermath. Under no arbitrage, default risk is compensated by an ‘yield pickup’ that can strongly attract aggressive investors via an investment-horizon effect in their optimal non-myopic portfolios. We show it by stating the optimal dynamic portfolio problem of Kim and Omberg (Rev Financ Stud 9:141–161, 1996) for a defaultable risky asset and by rigorously proving the existence of nirvana-type solutions. We achieve such a contribution to the portfolio optimization literature by means of a careful, closed-form-yielding adaptation to our defaultable asset setting of the general convex duality approach of Kramkov and Schachermayer (Ann Appl Probab 9(3):904–950, 1999; Ann Appl Probab 13(4):1504–1516, 2003).     

Spatial Allocation of Capital: The Role of Risk Preferences

Abstract

This paper considers a model of spatial allocation of investment capital under uncertainty. We demonstrate that the spatial concentration of economic activity depends upon properties of risk preferences deeper than risk aversion. The degree of so-called relative prudence unambiguously decides whether or not the diversification of income risk favours the geographic dispersion of economic activity. In our framework we relate risk diversification with economic integration. Then there exists risk preferences so that spatial concentration of industry and capital is not affected by the degree of economic integration or segmentation of the regions. We also study the impact of net return regressibility upon spatial allocation.

Affectation spatiale du capital: le rôle des préférences de risques

RÉSUMÉ La présente communication se penche sur un modèle d'application spatiale du capital-investissement en présence d'incertitudes. Nous démontrons que la concentration spatiale de l'activité économique est tributaire de propriétés de préférences de risque plus profondes que l'aversion au risque. Le degré de la soi-disant prudence relative décide sans ambiguïté si la diversification des risques de revenus favorise la dispersion géographique de l'activité économique. Dans le cadre de notre étude, nous examinons la diversification du risque en fonction de l'intégration économique. Il existe également des préférences de risque, qui font en sorte que la concentration spatiale de l'industrie et du capital n'est pas affectée par le degré d'intégration économique de la segmentation des régions.

Asignación espacial de capital: la función de las preferencias de riesgo

EXTRACTO Este trabajo considera un modelo de asignación espacial de capital de inversión en situación incierta. Demostramos que la concentración espacial de actividad económica depende más profundamente de las propiedades de las preferencias de riesgo que de la aversión al riesgo. El grado de la llamada prudencia relativa decide sin ambigüedad si la diversificación del riesgo de ingresos favorece, o no, la dispersión geográfica de la actividad económica. En nuestro marco, relacionamos la diversificación del riesgo con la integración económica. Asimismo, existen preferencias de riesgos para que la concentración espacial de la industria y el capital no sean afectados por el grado de integración o segmentación económica de las regiones.

     

Exploring the relationship between freedom from corruption and business governance in the Oceania region

This paper empirically investigates the relationship between Freedom from Corruption Index and business governance in the Oceania region by using the Pearson’s correlation coefficients, ordinary least square regression model and ordinary least square regression based decomposition analysis. This paper found that all eleven business governance indicators are positively correlated to Freedom from Corruption Index. Eight business governance indicators; namely, (1) trading across borders, (2) enforcing contracts, (3) resolving contracts, (4) ease of doing business, (5) registering property, (6) getting credit, (7) paying taxes and (8) starting a business significantly influences Freedom from Corruption Index. One standard deviation increase in eleven business governance indicators is associated with about 3.47 % point increase in Freedom from Corruption Index. All eleven business governance indicators contribute between 20 and 40 % differences in freedom from corruption in the Oceania region. All eleven business governance indicators contribute between 5.17 and 10.88 % to freedom from corruption in the Oceania region.     

紧缩性政策下银行信贷资金期限配置行为分析

从我国银行贷款传导渠道的典型事实出发,通过建立SVAR模型对紧缩性政策影响下我国银行业信贷资金期限配置行为进行研究,结果表明,当人民银行上调政策利率之后,银行出于防范利率上升所引致的净利息收益下降目的而增加短期贷款并减少中长期贷款,这就意味着,利率风险管理已成为影响银行信贷资金期限配置行为的决定因素。在此情况下,人民银行应充分发挥利率工具在促进信贷结构调整中的作用。     

Mean–variance econometric analysis of household portfolios

We investigate households' portfolio choice using a microeconometric approach derived from mean–variance optimization. We assume that households have heterogeneous expectations on the distribution of excess returns and that they cannot take short positions in risky assets. Assuming two such assets, we derive an explicit solution of the model characterized by four possible portfolio regimes, which are analyzed using two structural probit and tobit specifications with three latent state variables. Both specifications are estimated by weighted maximum likelihood on a cross‐section of US households drawn from the 2004 SCF. The tobit specification is simulated in order to evaluate the regressors' effects on regime probabilities and asset demands. We also assess to what extent the predicted state variables are consistent with the self‐reported expected returns and risk aversion elicited from the SCF questionnaire. Copyright © 2009 John Wiley & Sons, Ltd.     

Explaining efficiency in municipal services providers

This paper considers the provision of some important municipal services and applies the non-parametric double bootstrap Simar and Wilson (J Econ 136(1):31–64, 2007) model based on a truncated-regression to estimate the effect of a group of relevant factors, which include the political sign of the governing party and the type of management, on robust DEA (Data Envelopment Analysis) estimates. Previous conditions, like separability, must hold for meaningful first- stage efficiency estimates and second-stage regression. After some confusion in the literature, Simar and Wilson (J Prod Anal 36(2):205–218, 2011b) clarify that their work of 2007 actually defines a statistical model where truncated (but not censored, i.e., Tobit, not Ordinary Least Square) regression yields a consistent estimation of model features. They demonstrate that conventional, likelihood-based approaches to inference are invalid, and they develop a bootstrap approach that yields valid inference in second stage regressions when these are appropriate. The results reveal a significant relation between efficiency and all the variables analysed and that municipalities governed by progressive parties are more efficient.     

About the interactive influence of culture and regulatory barriers on entrepreneurial activity

In this paper cultural values and regulatory barriers to start-up are presented as characteristics of the business environment which influence the international differences in the level of entrepreneurial activity. A first objective of this paper is to measure the importance of a country’s cultural values in determining the national level of entrepreneurial activity, calculated by the Total Entrepreneurial Activity rate from the Global Entrepreneurship Monitor. Culture is studied using Schwartz’s value structure (Schwartz 1994). This allows for the differentiating of seven cultural orientations that are then arranged around three bipolar dimensions: Autonomy- Embeddedness, Egalitarianism-Hierarchy and Harmony-Mastery. The paper also studies the effect of regulatory barriers for business start-ups on the Total Entrepreneurial Activity in different countries. Regulatory barriers are determined using data from the “Doing Business” project of the World Bank. The role of cultural values and regulatory barriers in entrepreneurial activity is tested using data from 56 countries and Structural Equation Modeling. The paper shows that cultural values and regulatory barriers are not related to entrepreneurship in the same way in countries with differing levels of development. On the contrary, the strength and nature of the influence of both factors on entrepreneurial activity depends on a country’s per capita GDP. Furthermore, the impact of regulatory barriers on entrepreneurship is moderated by cultural values. Thus, the discouraging effect of the regulatory barriers on entrepreneurial activity is more important in those countries with a societal culture characterized by autonomy, egalitarianism and harmony values.     

Tests of risk premia in linear factor models

We show that statistical inference on the risk premia in linear factor models that is based on the Fama–MacBeth (FM) and generalized least squares (GLS) two-pass risk premia estimators is misleading when the β$\beta$’s are small and/or the number of assets is large. We propose novel statistics, that are based on the maximum likelihood estimator of Gibbons [Gibbons, M., 1982. Multivariate tests of financial models: A new approach. Journal of Financial Economics 10, 3–27], which remain trustworthy in these cases. The inadequacy of the FM and GLS two-pass t$t$/Wald statistics is highlighted in a power and size comparison using quarterly portfolio returns from Lettau and Ludvigson [Lettau, M., Ludvigson, S., 2001. Resurrecting the (C)CAPM: A cross-sectional test when risk premia are time-varying. Journal of Political Economy 109, 1238–1287]. The power and size comparison shows that the FM and GLS two-pass t$t$/Wald statistics can be severely size distorted. The 95% confidence sets for the risk premia in the above-cited work that result from the novel statistics differ substantially from those that result from the FM and GLS two-pass t$t$-statistics. They show support for the human capital asset pricing model although the 95% confidence set for the risk premia on labor income growth is unbounded. The 95% confidence sets show no support for the (scaled) consumption asset pricing model, since the 95% confidence set of the risk premia on the scaled consumption growth consists of the whole real line, but do not reject it either.