This is a great article that argues against cohabitation prior to marriage. Meg Jay, a clinical psychologist, makes some really strong points. For example, she states that:
Sliding into cohabitation wouldn’t be a problem if sliding out were as easy. But it isn’t. Too often, young adults enter into what they imagine will be low-cost, low-risk living situations only to find themselves unable to get out months, even years, later. It’s like signing up for a credit card with 0 percent interest. At the end of 12 months when the interest goes up to 23 percent you feel stuck because your balance is too high to pay off. In fact, cohabitation can be exactly like that. In behavioral economics, it’s called consumer lock-in.
Please see the full article here: http://tinyurl.com/883fs6m
