On a statement which issued at periodical of the French Population Institute, Belanger said that since the early 90s of last century , there is an increasing number of male being married to foreigner.

"We're beginning to see a change in how people view retirement," says George Leeson, co-director of the Institute of Population Ageing at Oxford.

The population Research Institute, a Virginia-based group linked to anti-abortion organisations in America, last week welcomed the news that the world's population was set to hit 7 billion this month.