This is something that helps to explain household income inequality in the UK. The idea that marriage is becoming something of a preserve of the rich.

Marriage is rapidly becoming the preserve of the wealthy, twice as common among those safely in the top tax bracket as among the least well-off.

Since 2001 those in the top social class, which includes company directors, military officers and university lecturers, have gone from being 24 per cent more likely to be married to 50 per cent more likely, figures from the Office for National Statistics show.

By the time they have children, nine in 10 of the wealthiest Britons are married. However, for those on the minimum wage or less, the figure is about half.

Cue all sorts of worries about the stability of family life and so on. And that's not what we're about here: chacun a son gout is our response to those sorts of concerns. However, this does link very strongly with something else that people claim to worry about a lot, the increasing inequality of household income in the UK.

For we've had something else happening as well. It's not just that the higher income people are more likely to marry: they're also more likely to marry other higher income people than they were in the past. This is of course part of the great economic emancipation of women of the past 50 years. Careers are something for both sexes, not only one. And as it happens people tend to marry those following much the same career path that they are. This is known as assortative mating.

Plug these two things together: professionals marrying professionals, non-professionals increasingly not marrying at all. We're going to end up with a lot of two high income households and a lot of low one income households. Thus, inevitably, household income inequality is going to increase.

And, short of telling people who they may marry or not, there's not a great deal that can be done about this.