Pricing interest-rate-derivative securities

This article shows that the one-state-variable interest-ratemodels of Vasicek (1977) and Cox, Ingersoll, and Ross (1985b)can be extended so that they are consistent with both the currentterm structure of interest rates and either the current volatilitiesof all spot interest rates or the current volatilities of allforward interest rates. The extended Vasicek model is shownto be very tractable analytically. The article compares optionprices obtained using the extended Vasicek model with thoseobtained using a number of other models.