>>15 Nonsense, it's common knowledge in family sociology.

http://www.psychpage.com/family/mod_couples_thx/cdc.html

http://www.family.org/cforum/fosi/marriage/cohabitation/a0025248.cfm

http://www.divorcemag.com/news/cohabitation.shtml

however, this article provides an interesting rebuttal:
http://www.unmarried.org/cdc2002.html

But really, if you're going to move in together and commit to each other anyway, why not just get married? And if you're not ready to take that step and especially if you're having serious doubts, live apart.