The British government says Sir Michael Barber, once an adviser to the former prime minist

er, Tony Blair, has changed pretty much every aspect of education policy in England and Wales, often more than once. "The funding of schools, the governance of schools, curriculum standards, assessment and testing, the role of local government, the role of national government, the range and nature of national agencies, schools admissions" —you name it, it's been changed and sometimes changed back. The only thing that hasn't changed has been the outcome. According to the National Foundation for Education Research, there had been (until recently) no measurable improvement in the standards of literacy and numeracy in primary schools for 50 years.

England and Wales are not alone. Australia has almost tripled education spending per student since 1970. No improvement. American spending has almost doubled since 1980 and class sizes are the lowest ever. Again, nothing. No matter what you do, it seems, standards refuse to budge. To misquote Woody Allen, those who can't do, teach; those who can't teach, run the schools.

Why bother, you might wonder. Nothing seems to matter. Yet something must. There are big variations in educational standards between countries. These have been measured and re-measured by the OECD's Programme for International Student Assessment (PISA) which has established, first, that the best performing countries do much better than the worst and, second, that the same countries head such league tables again and again: Canada, Finland, Japan, Singapore, South Korea.

Those findings raise what ought to be a fruitful question, what do the successful lot have in common？ Yet the answer to that has proved surprisingly elusive. Not more money. Singapore spends less per student than most. Nor more study time. Finnish students begin school later, and study fewer hours, than in other rich countries.

Now, an organisation from outside the teaching fold- McKinsey, a consultancy that advises companies and governments—has boldly gone where educationalists have mostly never gone: into policy recommendations based on the PISA findings. Schools, it says, need to do three things, get the best teachers; get the best out of teachers; and step in when pupils start to lag behind. That may not sound exactly "first-of-its-kind": schools surely do all this already？ Actually, they don't. If these ideas were really taken seriously, they would change education radically.

Begin with hiring the best. There is no question that, as one South Korean official put it, "the quality of an education system cannot exceed the quality of its teachers." Studies in Tennessee and Dallas have shown that, if you take pupils of average ability and give them to teachers deemed in the top fifth of the profession, they end up in the top 10% of student performers; if you give them to teachers from the bottom fifth, they end up at the bottom. The quality of teachers affects student performance more than anything else.

Yet most school systems do not go all out to get the best. The New Commission on the Skills of the American Workforce, a non-profit organisation, says America typically recruits teachers from the bottom third of college graduates. Washington, DC recently hired as chancellor for its public schools an alumna of an organisation called Teach for America, which seeks out top graduates and hires them to teach for two years. Both her appointment and the organisation caused a storm.

A bias against the brightest happens partly because of lack of money (governments fear they cannot afford them), and partly because other aims get in the way. Almost every rich country has sought to reduce class size lately. Yet all other things being equal, smaller classes mean more teachers for the same pot of money, producing lower salaries and lower professional status. That may explain the paradox that, after primary school