“…One of these rapid processes is the growth of non-traditional family forms, especially unmarried cohabitation. The increase of cohabitation is illustrated by the fact that the number of children born out of wedlock has risen (Bumpass and Sweet 1989, Kiernan 2000, Manning and Smock 1995, Paetsch, Bala, Bertrand and Glennon 2004, Perelli-Harris et al 2009, Seltzer 2000 and cohabitation is widely approved in western societies (Berrington 2001, Brown 2000, Seltzer 2000. Therefore, cohabitation can be seen as an equal partner to marriage.…”