FIRST there was Edison, the private business managing a handful of US state schools, marketing its wares in England's fledgling education action zones.
Now the other side of America's publicprivate debate has arrived in the UK, in the form of leading US economist Professor Alan Krueger.
While Edison's Benno C Schmidt Jr has been lunching anyone who will listen to press the case for handing state schools over to the private sector, the former chief economist at the US Department of Labor used a visit to the London School of Economics to defend the state system.
Professor Krueger, now professor of economics at Princeton University, says that claims that the state system has failed in America are not supported by the evidence. And as some even question the wisdom of continuing to invest public money in education, he says it is worth it.
His arguments will have some resonance in the UK where Labour has pledged to increase the proportion of public money spent on education, while at the same time encouraging private investment and insisting that further improvement can come from existing resources.
In another echo - of the UK's perennial debate over A-level and GCSE standards - Professor Krueger accuses opponents of selectively quoting test scores which suggest results are dropping. Unlike the UK, the US does not have key-stage tests taken by all pupils.
But the only standardised tests, he argues, have shown continued improvement, most of all among black students and those from deprived families - the very people who cannot opt out of the state system.
"The argument goes that US schools are crummy, and we should scrap them. I think that's dead wrong,'' he said.
"What's the evidence? They say test scores are no good - but they've gone up for the majority of students. They say schools don't take inputs and turn them into targets. But look at Tennessee."
The now-famous Tennessee project in the 1980s saw what Professor Krueger considers the only significant experiment into the effects of increased investment. Kindergarten pupils were put into classes of 15 for three years and their progress compared to other pupils in the standard classes of 22. Results were markedly higher.
Professor Krueger urges more such experimental research - something Labour might consider as it embarks on the experiment of action zones. He warned that anyone who thinks the private sector can do it better had to provide hard evidence.
"To alter the institutional structure of US schools radically without sufficient evidence that the 'reforms' would be successful is to put our children at risk."
Standards worldwide, page 22