The three traditional actuarial factors underlying life insurance premium calculations are mortality, interest, and expenses. Consequently, morbidity is the exception.
Mortality measures the statistical incidence of death within a population and is fundamental to estimating future life insurance death claims. Insurers use mortality experience and actuarial tables, adjusted through underwriting classifications, to estimate expected claim costs.
Interest represents the investment earnings the insurer anticipates receiving on premiums and reserves. Expected investment income helps offset the amount that must be collected directly from policyowners; other factors being equal, greater assumed investment earnings can reduce the required premium.
Expenses include acquisition costs, underwriting, commissions, policy administration, taxes, claims processing, and other operating expenses. These costs must also be incorporated into premium pricing.
Morbidity, by contrast, refers to the frequency or likelihood of sickness and disability. It is particularly important in health, disability income, and long-term care insurance pricing, but it is not one of the traditional three premium factors for life insurance.
The examination formula to remember is therefore: mortality + expenses − anticipated interest = fundamental life insurance pricing structure.
Study Guide Reference: Life Insurance Basics — premium determination; mortality; interest; expenses; distinction between mortality and morbidity.