Abstract

PIP: Data are analysed from the 1973 surveys of the Nigerian segment of the Changing African Family (CAFN) Project, which covered Yoruba women and men in Ibadan and the Western State of Nigeria. Of the 5874 women who were in union during the CAFN 1 survey, 54% reported that their husband had only 1 wife and 46% that their husband had more than 1 wife. Of the 1234 women in unions in the CAFN 2 survey, 49% reported monogamous husbands and 51% polygynous husbands. Differentials in fertility levels between women in monogamous unions and those in polygynous ones are investigated using mean number of children ever born as the measure of fertility. Factors examined include proportion of childless and infertile women, frequency of intercourse, age, educational level, religion, marital mobility (divorce) rank of wife and sexual abstinence. The CAFN 1 survey shows that wives of polygynists tend to be older than those of monogamists. Because of this the reported mean number of children ever born was higher for the wives of polygynists than for the wives of monogamists. When the data are standardized for the difference in age, the fertility levels of the women in the 2 types of unions were much closer to each other. When religion, education, abstinence, and occupation are also taken into account, it is observed that the 2 groups of women have similar levels of fertility. A multiple classification analysis was performed using number of wives of husband, educational level, religion and father's occupation as variables and occupation of spouse, place of birth, length of abstinence, contraceptive practice and age as covariates. The result also shows that the number of wives of the husband does not significantly affect the fertility level of women when other factors are taken into account. A high proportion of the Yoruba women are in polygynous unions and most of those in monogamous unions are potential wives of polygynists. Because of this, and particularly because most women try to have as many children as they can, the women in the 2 types of unions experience similar levels of fertility.