In September 2023, the finance company Lending Tree compiled data on the cost of raising a child from birth to 18 years of age. They collected information from multiple categories including rent, food, child care, apparel, transportation, entertainment, and health insurance premiums (and also took into account tax exemptions or credits families received). According to Lending Tree's study, the average cost of raising a child from birth to 18 years is $237,482. What important concept is missing from the Lending Tree estimate of the cost of raising a child? A full credit answer will state the concept; explain that concept in general terms; and then apply that concept to this situation.