Final answer:
Special mortality tables for annuities are used because annuitants typically live longer than the general life insurance buying population, requiring distinct actuarial assessments.
Step-by-step explanation:
Special mortality tables are used for annuities because annuitants are a select group of risks that generally live longer than purchasers of life insurance.
Unlike purchasers of life insurance who may reflect a broader cross-section of the population, annuity buyers are often planning for long-term financial stability, which suggests a different set of mortality risks and life expectancy factors.
Therefore, the insurance industry uses distinct actuarial tables for annuities to better account for this difference.