Abstract: | Abstract Differential growth in the use of oral anovulents is explored through construction of separate time series for Canadian women classified by religion, education, and nativity. The series suggest that native-born Roman Catholic women are as likely as native-born Protestant women to be using oral contraceptives by the terminal point of our series in 1967. The period of very rapid growth in the use of orals appears to have come to an end. Differential patterns of diffusion of oral contraception shown by the categories of women discussed, suggest sources of bias in the profile of an aggregate time series. |