College of Charleston sociology professor Von Bakanic said finances can explain why several generations may live under the same roof, and financial uncertainty also plays a role in the continued rise of unmarried couples.
“People don’t want to make the legal commitment, especially if they see the legal commitment as impermanent,” Bakanic said. “They see living together as an alternative to marriage and a trial for marriage, because they see the idea of marriage and divorce as extremely expensive.”
http://www.postandcourier.com/news/2011/aug/19/were-redefining-the-idea-of-family/