But the researchers say that since these unmarried unions are far more likely to break up, an increasing number of children are living in single parent families. They say that children brought up by lone parents do worse at school, are less likely to get good jobs and suffer more health problems.
John Ermisch, Professor of Economics at the University of Essex, said: 'The rise in births outside marriage is a real cause for concern. 'It is primarily attributable to the increase in people's tendency to cohabit in their first partnership and to have children within these unions. 'The instability of these unions means, however, that more British children will spend significant parts of their childhood in families with only one parent - and this appears to have long-term negative consequences.' [Christian Institute]