A new study appears to show that marriage doesn't really have any effect on children's development.
The Institute for Fiscal Studies looked at data on around 10,000 children and found that any advantages shown by children of married parents were down to differences in the social and economic status of those who decide to get married.
If you take other factors into account, marriage itself seems to have little or no impact on children's cognitive, social and emotional development, the Guardian reports.
However the Daily Mail has a rather different interpretation of the same story. Its headline reads: "Why children thrive with married parents".
The Mail claims that the think-tank says children are more likely to thrive if their parents are married.
However, it also admits that couples who are wealthier, healthier and better educated are more likely to get married in the first place.
It's a hot political issue with the Conservatives planning to encourage marriage through tax breaks.
They have proposed a tax break worth up to £150 a year for couples earning up to £44,000.
However, the IFS told the Guardian: "Our work shows that even if more couples did decide to get married in response to the small monetary incentive, such a policy would have a limited effect on young children's development."
There has been a big increase in the number of children born to unmarried couples in the last 25 years.
The Guardian says that up to 30% of all births in England and Wales were registered to unmarried parents living at the same address in 2008.
The study says married parents are twice as likely to have gone to university and be high earners and are more likely to be home-owners.
The study concludes: "We have shown that the children of married parents do better than the children of cohabiting parents in a number of dimensions, particularly on measures of social and emotional development at the ages of three and five.
"But we have also shown that parents who are married differ from those who are cohabiting in very substantial ways, particularly relating to their ethnicity, education and socio-economic status, and their history of relationship stability and the quality of their relationship even when the child is at a very young age.
"Once we take these factors into account there are no longer any statistically significant differences in these child outcomes between children of married and cohabiting parents."
So what do you think? Does marriage matter?
Source: The Guardian
Source: Daily Mail