Exploring the Decline in Induced Abortions in Spain: Behavioral Changes or Demographic Composition?

This study aims to determine the extent to which the changes in abortion incidence between 2011 and 2021 are attributable to shifts in women's behavior and to what extent they are due to changes in the composition of relevant characteristics such as age, origin, and educational level. This study analyzed two datasets: microdata from the Voluntary Terminations of Pregnancies register (2011–2021) and sociodemographic data from the Population and Housing Censuses (2011 and 2021). The datasets were merged using age, country of birth, and educational attainment, and Poisson regression models with Oaxaca-Blinder decomposition were applied to assess the role of compositional factors in abortion rate changes. Our findings highlight that shifts in abortion rates reflect a complex interplay between individual behaviors, social and economic changes, and population dynamics, such as immigration, educational shifts, and aging. More specifically this study shows that between 2011 and 2021, the crude induced abortion rate among women aged 12 to 52 in Spain decreased from 9.1 to 7.3 per 1,000 women. During this time, there was a rise in abortions among younger and older women, a decline in the proportion of Spanish women and those with lower education, and an increase among women with higher education. Compositional factors, particularly age and education, explain nearly 40% of the change. While origin composition counteracts this trend, immigrant groups largely reduced their abortion rates, and Spanish women showed slightly higher probabilities of abortion in 2021. Changes in education level also contributed to both compositional and behavioral effects.