FOR decades too many educationalists have succumbed to the tyranny of low expectations, at least when it comes to those at the bottom of the heap. The assumption has been that the poor, often black, children living in some of the world's biggest and richest cities such as New York, Los Angeles and London face too many challenges to learn. There was little hope that school could make any difference to their future unless the problem of poverty could first be “solved”, which it couldn't. Such attitudes consigned whole generations to the scrapheap. But 20 years ago, in St Paul, Minnesota, the first of America's charter schools started a revolution. There are now 5,600 of them. They are publicly funded, but largely independent of the local educational bureaucracies and the teachers' unions that live in unhealthy symbiosis with them. Charter schools are controversial, for three reasons. They represent an “experiment” or “privatisation”. They largely bypass the unions. And their results are mixed. In some states—Arkansas, Colorado, Illinois, Louisiana and Missouri—the results of charter pupils in maths and English are significantly better than those of pupils in traditional public schools. In others—Arizona and Ohio—they have done badly. Yet the virtue of experiments is that you can learn from them; and it is now becoming clear how and where charter schools work best. Poor pupils, those in urban environments and English-language learners fare better in charters (see article). In states that monitor them carefully and close down failing schools quickly, they work best. And one great advantage is that partly because most are free of union control, they can be closed down more easily if they are failing.

This revolution is now spreading round the world. In Britain academies, also free from local-authority control, were pioneered by the last Labour government. At first they were restricted to inner-city areas where existing schools had failed. But the Conservative-Liberal Democrat coalition has turbocharged their growth, and has launched “free schools”, modelled on a successful Swedish experiment, which have even more independence. By the end of this year half of all British schools will be academies or free schools. Free schools are too new for their performance to be judged; in academies, though, results for GCSEs (the exams pupils take at 15 or 16) are improving twice as fast as those in the state sector as a whole.

It is pretty clear now that giving schools independence—so long as it is done in the right way, with the right monitoring, regulation and safeguards from the state—works. Yet it remains politically difficult to implement. That is why it needs a strong push from national governments. Britain is giving school independence the shove it needs. In America, artificial limits on the number of charter schools must be ended, and they must get the same levels of funding as other schools.

The least we can do

In rich countries, this generation of adults is not doing well by its children. They will have to pay off huge public-sector debts. They will be expected to foot colossal bills for their parents' pension and health costs. They will compete for jobs with people from emerging countries, many of whom have better education systems despite their lower incomes. The least this generation can do for its children is to try its best to improve its state schools. Giving them more independence can do that at no extra cost. Let there be more of it.