EXPONENTIAL DURATION: A MORE ACCURATE ESTIMATION OF INTEREST RATE RISK

We develop a new method to estimate the interest rate risk of an asset. This method is based on modified duration and is always more accurate than traditional estimation with modified duration. The estimates by this method are close to estimates using traditional duration plus convexity when interest rates decrease. If interest rates rise, investors will suffer larger value declines than predicted by traditional duration plus convexity estimate. The new method avoids this undesirable value overestimation and provides an estimate slightly below the true value. For risk‐averse investors, overestimation of value declines is more desirable and conservative.     

DURATION,IMMUNIZATION, AND HEDGING WITH INTEREST RATE FUTURES

The recent advent of the interest rate futures markets has greatly enriched the hedging opportunities of market participants faced with undesired interest rate risk. The variety of futures contracts presently spans a number of instruments with different risk, maturity, and coupon characteristics. This paper modifies the concept of duration and extends the duration hedging approach to cases where futures contracts are used as the hedging instrument. The derived hedge ratios take into account differences in coupon, maturity, and risk for three different regimes. Usage of these hedge ratios should lead to more efficient hedging of interest rate risk.     

INTEREST RATE RISK HEDGING FOR DUE-ON-SALE MORTGAGES WITH EARLY TERMINATION

The impact of random early termination on the interest rate elasticity and the related implications of hedging a mortgage security are examined. The common approach to computing duration using average mortgage life is shown to be biased and insufficient. Because the prepayment distributions of mortgages tend to have wide dispersions, substantial errors result from using average mortgage life. These results are also applicable to other financial obligations subject to prepayment.     

DURATION,DEFAULT RISK,AND THE TERM STRUCTURE OF INTEREST RATES

We examine the interactive effect of default and interest rate risk on duration of defaultable bonds. We show that duration for defaultable bonds can be longer or shorter than default‐free bonds depending on the relation between default intensity and interest rates. Empirical evidence indicates that in most cases duration for defaultable bonds is much shorter than for their default‐free counterparts because of the negative relation between default risk and interest rates. Results suggest that the duration measure must be adjusted for the effects of default risk and stochastic interest rates to achieve an effective bond portfolio immunization.     

INTEREST RATE RISK AND EQUITY VALUES OF HEDGED AND UNHEDGED FINANCIAL INTERMEDIARIES

This paper uses an approach developed by Flannery and James to show that interest rate changes have different effects on equity values of hedged and unhedged financial institutions. Equity values of (generally unhedged) savings and loans are significantly more sensitive to unexpected interest rate changes than equities of (generally hedged) commercial banks. The interest rate sensitivity of (generally hedged) life insurance equities is similar to that of bank equities. Overall, the equity values of unhedged financial institutions are more sensitive to interest rate changes than the equity values of financial institutions that more closely balance the maturities of their assets and liabilities.     

INTEREST RATE RISK,MARKET VALUE,AND HEDGING FINANCIAL PORTFOLIOS

This paper derives theoretical hedge ratios for the financial portfolio that preserve its present value in the presence of interest rate risk. From a practical point of view and for any given portfolio, the existence of the financial futures market allows the investor to employ any of a number of different hedges, each of which approximately satisfies the theoretical condition. The theory indicates that wealth-preserving hedges depend on the interest elasticities (durations) of the spot assets and liabilities contained in the portfolio, portfolio leverage, and the interest elasticity (duration) of the financial instrument underlying the futures contract that is employed in constructing the hedge. Also, hedges designed to maintain net interest margin or net cash flow do not minimize exposure to interest rate risk.     

COMMERCIAL BANK RISK: MARKET,INTEREST RATE,AND FOREIGN EXCHANGE

Because of recent structural changes in the balance sheets of banks, regulatory changes in the risk-based capital requirements, and the recent adoption of mark-to-market accounting changes, interest rate risk remains an important issue for commercial banks and an important regulatory concern. Market, interest rate, and foreign exchange risk are estimated for a sample of commercial banks using ordinary least squares from 1986 to 1991. Consistent with earlier studies, the estimated coefficients continue to be unstable. We find that interest rate risk decreases and foreign exchange risk increases. Moreover, the results differ depending on practices of the bank (money center, superregional, or regional). We find evidence consistent with earlier studies that theorize foreign exchange risk is explained by unhedged foreign loan exposure.     

市场化条件下利率风险对商业银行的影响及其防范机制

我国利率市场化改革进程缓慢,整体上呈现先外币、后本币,先贷款、后存款,先批发、后零售的特点,并在管理观念、管理体制、管理技术和管理法规等方面存在一些问题。利率市场化真正实行后将产生许多风险,其中利率风险对商业银行的存贷款、收益、利率价格和内部利率政策等产生重大影响。对此作者提出从五个方面构建我国商业银行利率风险防范机制:建立提高资本充足率,迅速增强抗风险能力的机制;建立合理确定内部资金转移价格等为内容的产品定价体系;建立高效完善的资产负债管理组织体系;建立新业务和中间业务体系;建立商业银行利率风险规避工具的应用体系等。