Marriage and relationship stability – IFS Briefing uses MCS data

15 July 2010

A recently published Briefing by the Institute for Fiscal Studies (IFS), analysing data from the Millennium Cohort Study, shows that while cohabiting parents are more likely to separate than married ones, there is little evidence that marriage per se is the cause of greater stability between parents.

Parents who are cohabiting when their child is born are on average three times more likely to split up by the time their child is five than married parents (27% compared to 9%). However they are also typically younger, less well off, less likely to own their own homes, have fewer educational qualifications and are less likely to plan their pregnancies than married people. Once these differences between the two groups are accounted for, the difference in the likelihood of separation almost disappears, the Briefing says.

The IFS analysis shows that relationship stability is mainly determined not by marriage but by other factors such as age, education, occupation and income, and delaying and planning pregnancy. These factors are also influential in whether people choose to marry or not. So while married couples may have more stable relationships than those who are cohabiting, this is not because they are married, but because of the other characteristics they have that lead to marriage.

‘The evidence suggests that much of the difference in relationship stability between married and cohabiting parents is due to pre-existing differences between the kinds of people who get married before they have children, compared to those that cohabit’, said Ellen Greaves, research economist at the IFS.

Cohabitation, marriage and relationship stability IFS Briefing Note BN107 (IFS July 2010) Alissa Goodman and Ellen Greaves

The Briefing Note, which was funded by the Nuffield Foundation, is available at:

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