The Effect of Changing Sexual, Marital and Contraceptive Behaviour on Conceptions, Abortions, and Births

A model is proposed to estimate the number of conceptions during a single year using scarce survey data, official data on births and abortions for the two years following the survey, and some parameters on contraception failure. The model is fitted for 1979, 1989, 1994 to Puglia, a Southern Italian region with a population of 4 millions. Simulations are also produced.The decrease in births is caused mainly by the decline in wanted births, whereas the decline in abortions is caused by diffusion of the pill, IUD, and condom. The rapid increase in the proportion of never-married women explains the slow decrease in unwanted births and conceptions, compared to the fast decline in wanted ones. This situation is different compared to other Western countries (e.g. France, UK, and USA) where the decline in TFR during the 1960s and 1970s was largely caused by the decline in unwanted fertility, thanks to improved modern contraception and sterilisation.