The integrated impact of credit and interest rate risk on banks: A dynamic framework and stress testing application

Credit and interest rate risk are the two most important risks faced by commercial banks in their banking book. In this paper we derive a consistent and comprehensive framework to measure the integrated impact of both risks. By taking account of the repricing characteristics of assets, liabilities and off balance sheet items, we assess the integrated impact of credit and interest rate risk on banks’ economic value and capital adequacy. We then stress test a hypothetical but realistic bank using our framework and show that it is fundamental to measure the impact of credit and interest rate risk jointly.     

Basel-2 capital adequacy: Computing the ‘fair’ capital charge for loan commitment ‘true’ credit risk

This research makes two contributions: (i) to price analytically put option and extension premium embedded in a borrower-extendible commitment, and (ii) to compute the ‘fair’ capital charge that corresponds to the commitment ‘true’ credit risk. In doing so, the procedure replaces the BIS accounting-based concepts of credit-conversion factor, principal-risk factor, and initial term to maturity of irrevocable commitments with the market-based concepts of exercise-cum-takedown proportion and put value implicit in the borrower-extendible commitment, respectively. Finally, the approach is developed one step further to account for the borrowers' risk ratings by public credit agencies; this results in a two-dimensional (time-state of nature) risk-weighting system that applies to all commitment types.     

Bank capital regulation and credit supply

Banks can meet the need to increase their capital ratio either by issuing new equity or by reducing loans. It is generally known that banks prefer to reduce assets due to the high cost of equity. With a simple banking model we show that, if incumbent shareholders are to benefit, banks may prefer to reduce loans, even though they can recapitalize by issuing new equity without any cost. The result holds when banks hold relatively small amounts of long-term loans, or when the economy is in downturn.     

Efficiency and risk in European banking

We assess the inter-temporal relationship between bank efficiency, capital and risk in a sample of European commercial banks employing several definitions of efficiency, risk and capital and using the Granger-causality methodology in a panel data framework. Our results suggest that lower bank efficiency with respect to costs and revenues Granger-causes higher bank risk and that increases in bank capital precede cost efficiency improvements. We also find that more efficient banks eventually become better capitalized and that higher capital levels tend to have a positive effect on efficiency levels. These results are generally confirmed by a series of robustness tests. The results have potentially important implications for bank prudential supervision and underline the importance of attaining long-term efficiency gains to support financial stability objectives.     

The role of household and business credit in banking crises

Private credit expansions are an important predictor of subsequent banking crises. We revisit that result with a new dataset from developed and developing countries that decomposes private credit into household credit and enterprise credit. We argue that household credit growth raises debt levels without much effect on long-term income. Rapid household credit expansions generate vulnerabilities that can precipitate a banking crisis. Enterprise credit expansions can have the same effects but it is tempered by the associated increase in income. Our estimates show that household credit expansions have been a statistically and economically significant predictor of banking crises. Enterprise credit expansions are also associated with banking crises but their effect is weaker and less robust.     

Corporate credit risk modeling and the macroeconomy

Despite a surge in the research efforts put into modeling credit and default risk during the past decade, few studies have incorporated the impact that macroeconomic conditions have on business defaults. In this paper, we estimate a duration model to explain the survival time to default for borrowers in the business loan portfolio of a major Swedish bank over the period 1994–2000. The model takes both firm-specific characteristics, such as accounting ratios and payment behaviour, loan-related information, and the prevailing macroeconomic conditions into account. The output gap, the yield curve and consumers’ expectations of future economic development have significant explanatory power for the default risk of firms. We also compare our model with a frequently used model of firm default risk that conditions only on firm-specific information. The comparison shows that while the latter model can make a reasonably accurate ranking of firms’ according to default risk, our model, by taking macro conditions into account, is also able to account for the absolute level of risk.     

The macroeconomic sources of systemic risk in the banking sectors of five new EU member states

Rapid credit growth has been one of the most pervasive developments in recent years in Central and Eastern Europe. Our estimates support the hypothesis that the growth of credit and the amount of available finance might harm banking performance and deteriorate non-performing loans (NPL) dynamics, most probably due to the overheating of economies in the five NMSs. The procyclicality of banking sector performance and high economic activities growth is a signal of an economy overheating and therefore a slowdown in economic activity is likely to accelerate the growth of the NPL ratio.     

SAFE: An early warning system for systemic banking risk

This paper builds on existing microprudential and macroprudential early warning systems (EWSs) to develop a new, hybrid class of models for systemic risk that incorporates the structural characteristics of the financial system and a feedback amplification mechanism. The models explain financial stress using both public and proprietary supervisory data from systemically important institutions, regressing institutional imbalances using an optimal lag method. The Systemic Assessment of Financial Environment (SAFE) EWS monitors microprudential information from the largest bank holding companies to anticipate the buildup of macroeconomic stresses in the financial markets. To mitigate inherent uncertainty, SAFE develops a set of medium-term forecasting specifications that gives policymakers enough time to take ex-ante policy action and a set of short-term forecasting specifications for verification and adjustment of supervisory actions. This paper highlights the application of these models to stress testing and policy.     

Modelling the economic value of credit rating systems

In this paper we develop a model of the economic value of credit rating systems. Increasing international competition and changes in the regulatory framework driven by the Basel Committee on Banking Supervision (Basel II) called forth incentives for banks to improve their credit rating systems. An improvement of the statistical power of a rating system decreases the potential effects of adverse selection, and, combined with meeting several qualitative standards, decreases the amount of regulatory capital requirements. As a consequence, many banks have to make investment decisions where they have to consider the costs and the potential benefits of improving their rating systems. In our model the quality of a rating system depends on several parameters such as the accuracy of forecasting individual default probabilities and the rating class structure. We measure effects of adverse selection in a competitive one-period framework by parameterizing customer elasticity. Capital requirements are obtained by applying the current framework released by the Basel Committee on Banking Supervision. Results of a numerical analysis indicate that improving a rating system with low accuracy to medium accuracy can increase the annual rate of return on a portfolio by 30–40 bp. This effect is even stronger for banks operating in markets with high customer elasticity and high loss rates. Compared to the estimated implementation costs banks could have a strong incentive to invest in their rating systems. The potential of reduced capital requirements on the portfolio return is rather weak compared to the effect of adverse selection.     

A credit scoring model for Vietnam's retail banking market

As banking markets in developing countries are maturing, banks face competition not only from other domestic banks but also from sophisticated foreign banks. Given the substantial growth of consumer credit and increased regulatory attention to risk management, the development of a well-functioning credit assessment framework is essential. As part of such a framework, we propose a credit scoring model for Vietnamese retail loans. First, we show how to identify those borrower characteristics that should be part of a credit scoring model. Second, we illustrate how such a model can be calibrated to achieve the strategic objectives of the bank. Finally, we assess the use of credit scoring models in the context of transactional versus relationship lending.     

Macroeconomic announcements, volatility, and interrelationships: An examination of the UK interest rate and equity markets

This study investigates the intraday and daily pricing behavior of UK interest rate and equity index futures contracts. The paper initially examines the response of Short Sterling, Long Gilt, and FTSE100 to the release of scheduled macroeconomic announcements before employing dynamic time series techniques in order to reveal the nature of causal transmission patterns between these variables. In brief, short-term interest rates were found to be highly sensitive to indicators of prevailing economic conditions. However, the release of data important in the formation of inflationary expectations had a relatively subdued impact on long-term rates. Announcement effects appear somewhat ambiguous for the stock market. The analysis also reveals the bid-ask bounce and swift mean reversion in volatility to be important behavioral features of the return-generating process. Whilst the three variables appear to be bound by two cointegrating relationships, the tests for lead/lag relationships produce mixed results.     

Contagion risk in the Australian banking and property sectors

The Australian banking system emerged from the global crisis virtually unhurt, with most banks still profitable, adequately capitalized, and with AA credit ratings. Are there any risks or vulnerabilities in this success story? This paper analyzes Australia’s systemic banking risk and attempts to determine if this risk increased with the recent global crisis and whether this risk is related to the downturn experienced in the real estate market. We use extreme value theory to measure banks’ and property firms’ univariate Value at Risk, as well as multivariate intra-sector and inter-sector contagion risks. Of the 13 sectors analyzed, we find that the property sector exhibits the highest level of extremal dependence with the banking sector. The credit crisis significantly increased the probability of a bank or property firm crashing. Moreover, contagion risks significantly increased not only within the banking and property sectors, but also between those sectors.     

The economic determinants of interest rate option smiles

We address three questions relating to the interest rate options market: What is the shape of the smile? What are the economic determinants of the shape of the smile? Do these determinants have predictive power for the future shape of the smile and vice versa? We investigate these issues using daily bid and ask prices of euro (€) interest rate caps/floors. We find a clear smile pattern in interest rate options. The shape of the smile varies over time and is affected in a dynamic manner by yield curve variables and the future uncertainty in the interest rate markets; it also has information about future aggregate default risk. Our findings are useful for the pricing, hedging and risk management of these derivatives.     

Market conditions,default risk and credit spreads

This study empirically examines the impact of the interaction between market and default risk on corporate credit spreads. Using credit default swap (CDS) spreads, we find that average credit spreads decrease in GDP growth rate, but increase in GDP growth volatility and jump risk in the equity market. At the market level, investor sentiment is the most important determinant of credit spreads. At the firm level, credit spreads generally rise with cash flow volatility and beta, with the effect of cash flow beta varying with market conditions. We identify implied volatility as the most significant determinant of default risk among firm-level characteristics. Overall, a major portion of individual credit spreads is accounted for by firm-level determinants of default risk, while macroeconomic variables are directly responsible for a lesser portion.     

The evolution of cost-productivity and efficiency among US credit unions

Advances in information-processing technology have eroded the advantages of small scale and proximity to customers that traditionally enabled small lenders to thrive. Nonetheless, the membership and market share of US credit unions have increased, though their average size has also risen. We investigate changes in the efficiency and productivity of US credit unions during 1989–2006 by benchmarking the performance of individual firms against an estimated order-α quantile lying “near” the efficient frontier. We construct a cost analog of the Malmquist productivity index, which we decompose to estimate changes in cost and scale efficiency, and changes in technology. We find that cost-productivity fell on average across all credit unions but especially among smaller credit unions. Smaller credit unions confronted a shift in technology that increased the minimum cost required to produce given amounts of output. All but the largest credit unions also became less scale efficient over time.     

Pricing American interest rate options under the jump-extended constant-elasticity-of-variance short rate models

This paper demonstrates how to value American interest rate options under the jump-extended constant-elasticity-of-variance (CEV) models. We consider both exponential jumps (see Duffie et al., 2000) and lognormal jumps (see Johannes, 2004) in the short rate process. We show how to superimpose recombining multinomial jump trees on the diffusion trees, creating mixed jump-diffusion trees for the CEV models of short rate extended with exponential and lognormal jumps. Our simulations for the special case of jump-extended Cox, Ingersoll, and Ross (CIR) square root model show a significant computational advantage over the Longstaff and Schwartz’s (2001) least-squares regression method (LSM) for pricing American options on zero-coupon bonds.     

Asset financing with credit risk

This paper develops a model for the unified valuation of all forms of real asset financing, such as bank loans, leases, securitization vehicles, and credit guarantees, secured by assets that generate a stochastic service flow to the operator, or a rental stream to the lessor, and depreciate over a finite economic life to their scrap value. Examples include mobile equipment, such as aircraft, railroad equipment, ships, trucks and trailers, as well as energy generation assets, heavy factory equipment and construction equipment. In the event of obligor default, after a repossession delay and incurring costs of repossession, maintenance, re-marketing and re-deployment, the lender repossesses the asset and sells it on the secondary market and is, thus, subject to the risk of decline in the market value of the asset. The model we develop in this paper treats all forms of asset financing in a unified fashion as contingent claims on the collateral asset and the credit of the borrower. As an application, we estimate the collateral asset model on historical secondary market data for aircraft values and calibrate the financing model to the Enhanced Equipment Trust Certificates (EETCs) issued in 2007 by Continental Airlines and secured by a fleet of new aircraft. We then apply the calibrated model to value private market financing, including bank loans, leases, and credit guarantees, consistently with the capital market financing, and assess the impact of repossession delays on credit spreads. This analysis leads to a policy insight suggesting that bankruptcy laws limiting asset repossession delays lead to lower costs of asset financing.     

Banks’ capital buffer,risk and performance in the Canadian banking system: Impact of business cycles and regulatory changes

Using quarterly financial statements and stock market data from 1982 to 2010 for the six largest Canadian chartered banks, this paper documents positive co-movement between Canadian banks’ capital buffer and business cycles. The adoption of Basel Accords and the balance sheet leverage cap imposed by Canadian banking regulations did not change this cyclical behavior of Canadian bank capital. We find Canadian banks to be well-capitalized and that they hold a larger capital buffer in expansion than in recession, which may explain how they weathered the recent subprime financial crisis so well. This evidence that Canadian banks ride the business and regulatory periods underscores the appropriateness of a both micro- and a macro-prudential “through-the-cycle” approach to capital adequacy as advocated in the proposed Basel III framework to strengthen the resilience of the banking sector.     

A simple model of credit contagion

We propose a simple model of credit contagion in which we include macro- and microstructural interdependencies among the debtors within a credit portfolio. The microstructure captures interdependencies between debtors that go beyond their exposure to common factors, e.g., business or legal interdependencies. We show that even for diversified portfolios, moderate microstructural interdependencies have a significant impact on the tails of the loss distribution. This impact increases dramatically for less diversified microstructures.     

Asymmetric effects of the business cycle on bank credit risk

Prior empirical research on the relation between credit risk and the business cycle has failed to properly investigate the presence of asymmetric effects. To fill this gap, we examine this relation both at the aggregate and the bank level exploiting a unique dataset on Italian banks’ borrowers’ default rates. We employ threshold regression models that allow to endogenously establish different regimes identified by the thresholds over/below which credit risk is more/less cyclical. We find that not only are the effects of the business cycle on credit risk more pronounced during downturns but cyclicality is also higher for those banks with riskier portfolios.