THERE IS NOW remarkable agreement between Britain’s political parties about the proper goals of public policy. The debate about education provides a vivid example. Those who support the education White Paper argue that the reforms will increase social mobility, helping the most disadvantaged. The Bill’s opponents claim the reforms will decrease social mobility, locking in advantages already enjoyed by middle-class children. Behind the dispute lies agreement that education policy should be aimed at increasing social mobility.

Which goes to show that agreement among politicians is not necessarily something to celebrate. Social mobility is worthless. It is an absurd goal for public policy. That may sound like a strange or even unpleasant view. But it is no more than obvious once you know what “social mobility” means.

The Sutton Trust is an organisation devoted to increasing social mobility via education. It measures social mobility by comparing the income quartiles of parents and their adult children. If the child occupies a different income quartile from the parent, then we have a case of social movement. The more children who move out of their parents’ income quartiles, and the greater the distance they move, the greater the social mobility.

Those who recommend social mobility tend to focus on upward movements. John was born into a bottom-income quartile family, but now he is in the top quartile. Good for John. Alas, every upward social movement requires an equal quantity of downward movement. Just as a tennis player cannot climb the world rankings without others falling, so John’s ascent in the social rankings guarantees that others descend. And their losses must be exactly equal to John’s gain. When everyone is taken into account, it is simply impossible for social mobility to deliver a net benefit.

Why then should anyone want to increase the amount of it? Its supporters will answer that although social mobility is worthless in itself, it is an indicator of something valuable.

If the ranking of tennis players never changed, we would begin to suspect that the professional game was rigged. Equally, if no one ever did better or worse than his parents, we would begin to think that society was rigged. In a meritocracy, where people get ahead not through unfair privilege but through talent, effort and risk- taking, we should expect a certain amount of social mobility.

But how much? There is, after all, some social mobility in Britain. For example, 13 per cent of those born to bottom-quartile parents in 1970 were in the top quartile by 2000. Is that too few? Those who claim that there is not enough social mobility must think so. But how do they know? How much social mobility should we expect in a perfect meritocracy?

Consider these three facts. In modern economies, the intelligent and well-educated tend to have higher incomes. Intelligence and educational performance are largely inherited, through both nature and nurture. People tend to marry within their own social class. If these tendencies are very strong, then we should expect almost no social mobility in a meritocracy. Those with the attributes that get them to the top (merit, let’s call it) will produce children with merit, who will also get to the top and produce children with merit . . . and so on for generation after generation. If, on the other hand, these tendencies are only weak — if parents’ merit is not a good predictor of their children’s merit — then we should expect plenty of social mobility in a meritocracy.

What is the answer? How strong are these tendencies? How much mobility should we expect in a meritocracy? I do not know. And I’ll warrant no one else does either, including our would-be social mobilisers, who simply ignore the issue. But then how can they be so sure that there is too little social mobility?

Confusing social mobility and meritocracy is not only ignorant, it is dangerous. For the easiest way to achieve social mobility is not by increasing meritocracy but by direct government intervention: by simply pushing some people up, and therefore others down, the social ladder.

Such policies already exist. The Government demands that the best universities admit most of their students from state schools regardless of the relative merits of applicants from independent schools. This policy aims at increasing social mobility, but directly at the expense of meritocracy.

Until recently, the Labour Party was devoted to creating a society in which social mobility was impossible, a society where there was only one rung on the social ladder. The history of the 20th century showed that goal to be ruinous. So now Labour seeks equality of opportunity rather than equality of outcome. But the poor old socialists cannot get the hang of their new philosophy. They keep forgetting that we cannot have equality of opportunity if the Government engineers some specific outcome: be it that everyone has the same income or that everyone’s income differs from their parents’.

When your rivals in politics are profoundly confused, agreeing with them is nothing to celebrate.

Jamie Whyte is a philosopher and author of Bad Thoughts: A Guide to Clear Thinking

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