Family Income and Demand for Child: An Alternative Model and Some Evidences

In spite of nonhuman species، determining quantity of children among human beings is the result of a decision-making process. There is a set of factors that influences this decision in which income is the most important and ambiguous of them. Using an optimization model in which utility of parents depends the amount of consumed goods and number of their children، it is shown that increase income، ceteris paribus leads to increase in demand for child but the total effect could be negative. The evidence from Tehran suggests that the income effect is positive but statistically insignificant. Totally، the total effect of an increase in income is negative and statistically significant.