In rural areas, continued decline in childhood death means that at some point parents realize they need not require so many children to be born to ensure a comfortable old age. As childhood death continues to fall and incomes increase parents can become increasingly confident that fewer children will suffice to help in family business and care for them in old age.

Increasing urbanization changes the traditional values placed upon fertility and the value of children in rural society. Urban living also raises the cost of dependent children to a nuclear family (education and clothing costs increase).

Increasing female literacy, employment of women, and valuation of women beyond childbearing and motherhood may all affect the number of children a woman chooses to have.

Improvements in contraceptive technology, availability, and education also all impact birth rates.