Exercise
A financial analyst is assessing the interest rate sensitivity of a fixed-payment structured settlement. The current present value of this settlement, based on prevailing market rates, is $150,000. The Macaulay duration of the settlement's cash flows, given the current market discount rate, is 10.0 years. The current annual effective market discount rate used for valuation is 4.0%. The analyst needs to estimate the immediate impact on the present value of the structured settlement if the market discount rate were to decrease by 25 basis points (0.25%).
Using this information, calculate the approximate change in the present value of the structured settlement.
- -$3,750.00
- -$3,605.77
- $3,605.77
- $3,750.00
- $3,906.25
The objective is to calculate the approximate change in the present value (PV) of a structured settlement due to a change in the market discount rate. We are provided with the following information:
- Current Present Value ([math]PV[/math]): [math]$150,000[/math]
- Macaulay Duration ([math]MacDur[/math]): [math]10.0[/math] years
- Current Annual Effective Market Discount Rate ([math]i[/math]): [math]4.0\% = 0.04[/math]
- Change in Market Discount Rate ([math]\Delta i[/math]): A decrease of [math]25[/math] basis points, which is [math]-0.25\% = -0.0025[/math].
The approximate change in the present value of a financial instrument can be estimated using its modified duration. The formulas required are:
- Modified Duration: The modified duration ([math]ModDur[/math]) is calculated from the Macaulay duration as:[[math]]ModDur = \frac{MacDur}{1+i}[[/math]]
- Approximate Change in Present Value: The approximate change in present value ([math]\Delta PV[/math]) is given by:
Using the given Macaulay duration and the current market discount rate, we calculate the modified duration:
Now, we apply the formula for the approximate change in present value, substituting the known values:
- The approximation of change in present value using duration is a first-order approximation and assumes a linear relationship between interest rates and bond prices, which is generally valid for small interest rate changes.
- Macaulay duration measures the weighted average time until a bond's cash flows are received, while modified duration measures the percentage change in a bond's price for a 1% change in yield.
- To use the duration approximation for price changes, Macaulay duration must first be converted to Modified Duration by dividing by [math](1 + i)[/math], where [math]i[/math] is the periodic yield.
- A decrease in interest rates typically leads to an increase in the present value (price) of a bond, and vice-versa, as reflected by the negative sign in the approximation formula [math]\Delta PV \approx -PV \times ModDur \times \Delta i[/math].
- Basis points must be converted to decimal form (e.g., 25 basis points = 0.0025) before being used in calculations.