Age at marriage and fertility in Java-Bali, a question of natural or controlled fertility.

Controlled fertility, as defined by Henry (1961), is fertility achieved in a stituation where the behavior of couples is bound to parity, that is the number of children they aim to have, while natural fertility is a fertility achieved under the absence of deliberate birth control practices. Based on this definition, the fertility of women in Java-Bali aged 40 years and over in 1976 was examined. Age at 1st marriage of the Java-Bali women was examined in relation to their subsequent fertility following their 1st marriage, namely, their 1st birth interval, their ages at the birth of their 1st child, intervals between births (up to the 4th birth), and their estimated age at completion of childbearing. The data used were derived from the 1976 Indonesia Fertility Survey. This examination of the impact of age at marriage on fertility produced evidence of a natural fertility situation. Women who married before their 15th birthday had, on the average, twice as many children as those who married at age 25 years or older. The differences in the mean number of children ever born between women who married at ages 15-17, 18-19, 20-21, and 20-24 were small. A marked decline was shown among the women who married at age 25 or older. Women who married before their 15th birthday had the longest 1st birth interval of 44.1 months. The interval then decreased with increasing age at marriage with the lowest birth interval reached by the women married at ages 22-24 years old. The interval rose again for women married at 25 years or older. Examination of the subsequent births yielded the impression that women who married older tended to have their children in rapid succession and thus reached the 4th birth quicker than those who married younger. This evidence is not indicative of Henry's catching up effect but rather an indication of peak level of fecundity in the early years of marriage for those who married older. The examination of the estimated age at completion of childbearing and the average length of the childbearing span by age at marriage showed that women who married younger had a longer childbearing span, which allowed them to produce more children, than their counterparts who married older. This increase of fertility with increased exposure time is consistent with natural fertility. There was a tendency for women married later to have had a shorter duration of marriage to reach the 4th birth than women who married younger. It is concluded that the differences of completed parity by age at marriage are largely due to the differences in the length of exposure to the risk of childbearing and thus are consistent with a natural fertility situation.