But a sudden increase in the woman's earnings, or having three or more children increases the risk of couples breaking up, according to a study conducted by the Institute of Social and Economic Research at the University of Essex.
The study, presented today at the Royal Economic Society's annual conference in Nottingham, was based on surveys of 5,500 couples with at least one child between 1991 and 1997. It showed that far from children holding couples together, the greater the number of children the couple had, the more likely the relationship was to break down. This risk increased if the children were more than six years old.
Rene Boheim, one of the report's authors, said: "The more children, the greater the strain, with three appearing to be the breaking point."
Previous research has shown that a sudden change in economic fortune for better or for worse causes friction between couples which was thought to lead to a greater risk of breaking up. But the research shows that money is more likely to bind couples together. Those whose income suddenly exceeds their expectations are 30 per cent more likely to stay together.
"It is not how much money they have but how much money they expect to have," said Mr Boheim. "People who find themselves surprisingly better off have fewer problems and less friction with their partners. They find they are in a more fulfilling situation."
Those who suddenly found themselves in a worse position were no more likely to split up than couples who were in exactly the position they expected to be. The average rate of divorce for this group was 3 per cent. Higher women's earnings increased the likelihood of couples splitting up. A breakdown of tradition and female financial independence were seen to be the main driving forces for the increased risk of separation.
The divorce rate is higher among women who earn a lot of money.
"If women have their own earning power and are financially independent they will put up with less," said Professor John Ermish, who co-authored the report.
The report looked at both married and cohabiting couples. Cohabiting couples were more than twice as likely to end their relationship than couples who were married.Reuse content