Answer: effective duration.

**Explanation:** Key rate duration measures the sensitivity of a bond's price to changes in specific key rates along the yield curve. When there is a **parallel shift** in the benchmark yield curve (meaning all rates change by the same amount), the sum of key rate durations equals the bond's **effective duration**. **Key Points:** 1. **Effective duration** measures price sensitivity to parallel shifts in the yield curve. 2. **Key rate durations** decompose interest rate risk across different maturities on the yield curve. 3. For parallel shifts, the combined effect of all key rate durations equals the effective duration. 4. **Modified duration** assumes a flat yield curve and parallel shifts, but it's based on the bond's yield to maturity rather than the benchmark curve. 5. **Macaulay duration** is a weighted average time to receive cash flows, not a direct measure of interest rate sensitivity. Therefore, for parallel shifts in the benchmark yield curve, key rate durations collectively indicate the same interest rate sensitivity as effective duration.

Author: LeetQuiz .