While the authors of The Spirit Level were wrong they did at least have an interesting theory. Which was that inequality is bad for everyone, not just for those being unequaled upon by society. As I say, they were wrong, but let us see if we can take the same basic idea, that x is better for everyone, and then see if those who swooned over The Spirit Level will support it. 

An interesting x to explore is the effect of private schooling upon general levels of education. We all know that going to a school where at least an attempt to teach something is better for the pupil than one where little to nothing is taught. Private schools certainly benefit those who go to them. Ah, but our lefty friends then tell us, but this leaves those left in the State schools worse off and that will never do.

But what if the existence of private schools makes all better off? What if the very fact that there is competition, examples of different ways of doing things, raises the standard of education for everyone, whether they go to private or State schools? For that does indeed seem to be the case as a paper in the Economic Journal shows (£ so no link). The essence of the finding, looking at a century of records over 29 countries is:

Countries with a higher proportion of students enrolled in private schools score higher on internationally comparable exams taken by 15 year olds. Cross-national research published in the Economic Journal shows that competition from private schools improves achievement for both state and private school students while decreasing overall spending on education.

For example, a 10% increase in enrolment in private schools improves a country’s mathematics test scores in PISA (Programme for International Student Assessment) by almost half a year’s worth of learning. A 10% increase in private school enrolment also reduces total educational spending per student by over 5% of the OECD average.

Yes, competition works. No doubt all those currently opposing academies, even the very existence of private education, will now support them? For, as the man said, when the evidence changes I change my mind sir, what do you do?