Married parents are four and a half times more likely to stay together than cohabitees, according to a new report.
The study also shows that marriage has become more stable for children in recent years, as fewer married couples separate.
Three quarters of couples in 2006 who were married when they had their first child were still together when the child turned 16, the report showed.
This rose from 70 per cent who had stayed together in 1992.
However, only 16.5 per cent of couples in 2006 who were cohabiting at the birth of their first child stayed together until the child reached 16. More than half of those had married.
This shows that marriage provides the “best environment for both the individuals involved and their children”, according to the Director of the Jubilee Centre, the organisation behind the findings.
The study also highlighted figures released earlier this month which estimated the cost of family breakdown at £41.7 billion.
Dr Guy Brandon, one of the report’s authors, described the figure as “enormous”.
The authors also raised concerns about proposed changes to the law on rights for cohabitees.
The rules, proposed by the Law Commission in 2007, would mean that partners who have lived together for five years would have the same legal rights as a husband or wife.
But the Jubilee Centre report said that by “incentivising cohabitation” the rules would “disadvantage a much larger number of people, resulting in increased cost to the taxpayer”.
Dr John Hayward, Director of the Jubilee Centre, said: “All the evidence suggests that families headed by married, biological parents who have not previously lived together provide the best environment for both the individuals involved and their children.
“This has huge personal, social, economic and political consequences for us all.”
Debate has raged in recent months over the importance of marriage and its place in the tax system.
The Conservatives say they will recognise marriage in the tax system but have not laid out specifics as yet.
However David Cameron has made clear that any tax plan for married couples will also include those in same-sex civil partnerships.
The Tory plans have been labelled as ‘social engineering’ by Labour and a “bribe” by the Liberal Democrats.
Earlier this month CARE, a Christian charity, showed that UK married couples with children are paying a third more in tax than similar families in other developed countries.
Just last month the importance of marriage for the welfare of children was demonstrated in a report released by the Bristol Community Family Trust.
The results of the report showed that only three per cent of couples who stay together until their child is 15 are unmarried and most cohabiting couples either get married or split up.
The findings suggested that “the trend away from marriage is responsible for the rise in family breakdown”.