THE formula for a happy marriage has been discovered – a man should choose a wife who is smarter and at least five years younger than him.

This, according to the findings of a British study which appeared in the European Journal Of Operational Research, reported BBC.

The research, called Optimising The Marriage Market, saw academics including Dr Emmanuel Fragnière of the University of Bath, interviewing 1,534 Swiss couples who were either married or in a serious relationship.

Five years later, they followed up with 1,074 of the couples to see which of them had separated. Their results showed a clear pattern.

Couples with the best chance are those where a woman with a superior education marries a man who is five or more years older than herself.

Neither should be a divorcee.

If the wife is five or more years older than her husband, they are more than three times as likely to divorce than if they are the same age.

If the age gap is reversed, and the man is older than the woman, the odds of marital bliss are higher.

If the woman is better educated than the man, they are eight times as likely to stay together than the uneducated couple, and three times more secure than if the husband were more of a bookworm than the wife.

Unsurprisingly, analysis of the data showed that the most stable couples were those who had never divorced, said Daily Mail. The most unstable are where only one has had a divorce.

The report concluded: “It appears men and women ‘choose’ their mates on the basis of love, physical attraction, similarity of tastes, beliefs and attitudes, and shared values.

“However, the longevity of marriages also depends on objective factors. Matching individuals according to a small number of objective criteria such as age, education and cultural origin may help reduce divorce.”

These findings predict a happy future for pop star Beyonce Knowles, 28, and rapper husband Jay-Z, 39.

Not only is she younger than her husband, she is better educated – Beyonce has a high school diploma, unlike Jay-Z. But the study may not be welcomed by Michael Douglas, 65, who was a divorcee before marrying Catherine Zeta-Jones, 40.