When will young adults get the message that living together does not increase their chances of a lasting marriage? New analysis of US national data shows that, on average, cohabitation actually decreases by 6 percentage points the likelihood of marriage lasting 10 years or more.

Despite earlier research showing this same pattern, more and more young adults delay marriage and cohabit: nearly two out of three women in their late 30s have done so, according to this study of 2002 data by the National Centre for Health Statistics.

However, the effects vary by education:

Half of couples who cohabit marry within three years, the study found. If both partners are college graduates, the chances improve that they will marry and that their marriage will last at least 10 years.

“The figures suggest to me that cohabitation is still a pathway to marriage for many college graduates, while it may be an end in itself for many less educated women,” said Kelly A. Musick, a professor of policy analysis and management at Cornell.

This means, of course, that an increasing number of children are born to unmarried parents who are likely to stay that way, often with the parents living apart. Black children in the US are particularly at risk in this respect: their parents are less likely to get married (only 39 per cent of black women have married by age 44) and even if they do, the likelihood of their remaining married for 10 years of more is only 50 per cent.

Interesting intergenerational effect of marital instability noted:

Women who were not living with both of their biological or adoptive parents at 14 were less likely to be married and more likely to be cohabiting than those who grew up with both parents.

Also interesting the messages in headlines used for different reports -- as noted by the folks at Smartmarriages.com

NY Times: Living Together First Doesn¹t Make Marriage Last, Study Finds

USA Today: Report: Cohabiting has little effect on couples' success in marriage

MSNBC: Living together does lead to marriage 2 in 3 who cohabit tie the knot within 5 years, CDC says

Reuters: Marriages last longer than living together?

ABC NEWS: Moving In Together Before Wedding Can Decrease Chances of Having a Lasting Marriage, Study Says; CDC Survey Says Cohabitation Isn't Always a Good Thing, Couples Say It's All About Love