Final answer:
In bond portfolio analysis, starting with the duration of the bonds is recommended by PRI as it gives a comprehensive measure of a bond's sensitivity to interest rate changes.
Step-by-step explanation:
When analyzing a bond portfolio, Portfolio Risk Index (PRI) suggests starting with the duration of the bonds. Duration serves as a measure of a bond's sensitivity to interest rate changes and is expressed in years. It considers the bond's coupon rate, yield to maturity, and the time to its maturity date, providing a comprehensive measure of interest rate risk. While credit rating, maturity dates, and yield to maturity are also important factors to consider, duration offers a more complex understanding. It reflects the weighted average time to receive all cash flows from the bond, giving an investor a sense of how long it will take to recoup their investment considering both time and interest rate changes.