Consistency and predictive ability of fertility preference indicators: longitudinal evidence from rural India.

CONTEXT Ideal family size and desire for an additional child are the two most commonly used fertility preference indicators. However, little is known about the consistency over time of responses to each measure, the consistency between the two indicators or the predictive value of these indicators in India. METHOD Longitudinal data from the 1998-1999 National Family Health Survey and a follow-up survey conducted four years later were analyzed to determine the consistency of responses to the two fertility preference indicators (both over time and between indicators) and to determine whether baseline responses were associated with subsequent fertility, unwanted births and contraceptive use. RESULTS Responses on the measure of ideal family size were consistent at the two time points for 53% of nonsterilized women. Eighty-two percent of women who explicitly said in 1998 that they did not desire more children responded identically in 2002, although about half of these women had given birth in the intervening period. The indicators were associated with each other: Among women with at least one son, 79% of those who had attained or surpassed their ideal family size said they wanted to stop childbearing, compared with 18% of those who had not. Both indicators predicted future fertility, unwanted births and contraceptive use, particularly among women who had a son. CONCLUSION Both indicators are useful in understanding future fertility behavior. As the prevalence of son preference declines in India, the predictive ability of the indicators is likely to improve.