Household desires for children are expressed in terms of an indifference map representing the subjective degree of satisfaction derived by the parents for all possible combinations of commodities and children. Each individual indifference curve portrays a locus of commodity-child combinations that yield the same amount of satisfaction. Any point (or combination of goods and children) on a “higher” indifference curve that is, on a curve farther out from the origirepresents a higher level of satisfaction than any point on a lower indifference curve. But each indifference curve is a “constant satisfaction” locus.