Martin Sewell: You may have social mobility, promote fairness, or attempt to help the “squeezed middle”. But you are unlikely to be able to deliver all three.

Martin Sewell is a family lawyer

As I followed yesterday's discussions about “social mobility”, I could not help but recall a mathematical friend’s dismay at hearing a left wing politician assert that he would not be content until everybody received “above average earnings”.

He patiently explained that an average had to be precisely at the mid-point, and that there could not be a majority above that - but plainly such subtlety is beyond the populist, whether of the left or the right.

Lest you think this an unusual aberration, I have just listened to an archived radio clip of Gordon Brown arguing that he wanted social mobility “for the majority”. By implication he wanted most of us to be on the way up - and yet my friend’s precision demonstrates that such an outcome, however rhetorically desirable, simply cannot happen. We may all be affected by social mobility - but half of us can't gain from it.

Life often presents difficult choices and priorities.

As a family lawyer conducting financial disputes, I often used to make a similar point. I would advise clients that  “You can have quick, you can have thorough or you can have cheap, but you are unlikely to be able to secure all three.”

I am sure that most working people can offer similar necessary trade-offs in medicine, commerce and industry. We weigh costs against outcomes, we take calculated risks to save time or money - we do such things all the time. We live in the world of reality and compromise, whereas too many politicians have no such practical experience, over-reach in their promises and don't considering the complex truth of the situation.

We are debating social mobility as if everyone shares a positive interest in it happening. Yet inevitably, for everyone moving up, there will be somebody moving down. They may consider the weighted advantages given to their aspirant competitors - or their children - to be very “unfair”.

Those in “the squeezed middle”  find themselves in double jeopardy; they or their offspring will find themselves being outgunned from sinking old Etonians or by positive discrimination - assisted poorer children rising from below - or by newly arrived immigrants who have been offered the chance to ‘fairly compete” in our jobs market.

The truth is: you may have social mobility, you may promote fairness, or you may attempt to assist the “squeezed middle”, but you are unlikely to be able to deliver all three.

I suspect that we shall be hearing much on the subject from Martin Luther Millband, and I hope some Conservative backbenchers will invite him to explain how precisely he strikes the difficult balance, and in particular which 50% of the population he wants to see enjoying downwards mobility in income, education, and health care.

In the economic sphere he could usefully consider that there is one way out which he may find the best of the difficult alternatives in delivering a fairish outcome for the best deserving. It is called “meritocracy”.