Educational vouchers were proposed by Milton Friedman in the 1950s as a method of improving the quality of elementary and secondary education.
In recent years, there has been renewed interest in the idea, particularly in the United States where private schools are regarded as a refuge from the blackboard jungle.
A common theme of all voucher proposals in the US is that parents who choose to send their children to private schools would receive a voucher from the government that would cover some or all costs.
But the issue has been bitterly contested. Experimental voucher systems are in place in Milwaukee, Cleveland and Florida. In Cleveland last year, more than 4,000 students used vouchers worth US$2,500 (HK$19,500) to attend private schools. Cleveland adopted vouchers seven years ago, but it was only last June, in a landmark Supreme Court ruling, that the system was deemed constitutional. President George W. Bush said the move 'clears the way for other innovative school choice programmes, so that no child in America will be left behind'.
'School choice offers proven results of a better education, not only for children enrolled in the specific plan, but also for children whose public schools benefit from the competition,' the president said.
'This landmark ruling is a victory for parents and children throughout America.'