2nd Demographic Changeover (SDT)
Advocates regarding SDT theory think nonmarital childbearing to-be certainly its trademark facets (Lesthaeghe and you will Surkyn 2002; van de- Kaa 2001). With its simplest conceptualization, the fresh new SDT relates to a great deal from interconnected habits, plus cohabitation, declines otherwise waits in-marriage, postponement out of childbirth, and you will lower than-replacement for levels of virility (Lesthaeghe and you can Neidert 2006; McLanahan 2004; Sobotka mais aussi al. 2003). Dirk van de- Kaa (2001) next specified that behavioral alter of your SDT take place in a series, starting with declines throughout the overall fertility rates and you will moving on thanks to 15 levels you to definitely culminate regarding the decoupling out-of relationships and you will virility.