Final answer:
The modified duration measures a bond's price sensitivity to interest rate changes and requires calculating the present value of cash flows. Calculating it for a portfolio involves a weighted average based on market values. Exact figures cannot be determined here without specific formulas or a financial calculator.
Step-by-step explanation:
The question asks for the calculation of the modified duration of a portfolio consisting of two bonds, Bond A with a par value of $1,000, an 8% annual coupon, and an effective interest rate of 6%, and Bond B with a par value of $1,000, no coupons (zero-coupon bond), and an effective interest rate of 7%. The modified duration is used to measure the sensitivity of a bond's price to changes in interest rates, which indicates the percentage change in price for a one percent change in yield.
To calculate the modified duration of each bond, we would typically calculate the present value of the bond's cash flows, weight each cash flow by the time until receipt and then adjust that by the bond's yield to maturity. However, for the purpose of this explanation, and without specific bond valuation formulas or a financial calculator, it is not possible to provide an exact numerical answer. It is important to note, the modified duration of Bond B would be simply equal to its time to maturity since it is a zero-coupon bond.
Calculating the modified duration for a portfolio involves taking the weighted average modified duration of the individual bonds based on their market values. Once the modified durations for each bond are calculated, they are multiplied by their respective market values and added together, then divided by the total market value of the portfolio to give the portfolio's overall modified duration.
When considering changes in interest rates, we can observe that bonds with lower interest rates will sell for less than face value when the market interest rates rise, and those with higher rates will sell for more when market rates fall. This is directly related to the concepts of bond yield and modified duration.