A time series analysis of Swedish illegitimacy rates, 1911-1974.

Using a sociodemographic model of the determinants of illegitimacy rates, a multivariate regression analysis of annual change in age-specific Swedish illegitimacy rates is applied to the 1911-74 period. The proxy measure of change in sexual activity was significant for all age groups. Legitimation rates for out-of-wedlock conceived births were significant for all ages except teenagers, and the final predictor, women's status, was significant for all ages except women 35-44. Explained variance for annual change was highest among ages 20-24 (66%), 25-29 (66%), and 30-34 (63%) and lower among teens (34%) and women 35-44 (47%). These results support earlier research that used a sociodemographic model to explain post-World War II change in cross-national illegitimacy rates among 23 developed countries.