pound;200,000: true value of top reception teachers
An excellent early-years classroom experience increases the collective lifetime earnings of one class of pupils by pound;200,000, according to Harvard research, which places a monetary value on these teachers' input for the first time.
This works out at pound;10,000 of increased earnings per pupil, compared with peers from similar backgrounds whose early-years teaching was less effective.
As a result, the group of six Harvard economists is arguing that the best early-years teachers should be commanding salaries equivalent to their educational value: pound;200,000 a year.
The researchers examined the long-term effect of a stand-out kindergarten teacher on 12,000 children who had been part of an educational experiment in Tennessee in the 1980s. They looked at the impact that these teachers had on the eventual earnings of their former pupils, now aged around 30.
The research found that adults who received better early-years education were likely to have significantly higher salaries than their poorly educated peers.
Five-year-olds who made the typical improvements to be expected following a good early-years education would earn an additional $1,000 (pound;628) a year by age 27. This could be expected to increase proportionately throughout their working lives.
The study also showed that pupils who learnt more in kindergarten were more likely to go on to university than their peers, and less likely to become single parents. They had better general health and were more likely to be saving for retirement.
Chris Davis, of the National Primary Headteachers' Association, is unsurprised. "The influence of early years on a child's long-term education is crucial," he said. "I always felt that the most important job in the whole school was the reception teacher. The better the experience of the child pre-five, the better value you will get from them post- five."
Russell Hobby, general secretary of heads' union the NAHT, agrees. "If you get early years right, then it helps primary," he said. "And if you get primary right, then it helps secondary. The problem with our system is that secondary and higher education dominate the debate. We should reverse the order of attention."
The economists argue that being taught by an above-average teacher increases the collective lifetime earnings of a class of five-year-olds by $320,000 (pound;200,847). This, they say, suggests that a stand-out early-years teacher is worth pound;200,000 a year.
"In the current climate, that would be wishful thinking," Mr Hobby said. "But I welcome the recognition of value, and the respect that comes alongside that.
"The contributions that teachers make to society and the economy are immense. I would argue that teachers create more value than any other job in society: surgeons, lawyers and politicians all depend on teachers to get them where they are."
The Tennessee experiment randomly assigned pupils to a kindergarten class, equivalent to Year 1 in English schools. As a result, each class had pupils from a range of socio-economic backgrounds.
Those classes with pupils from slightly higher socio-economic backgrounds did tend to do better in standardised tests. Similarly, pupils in classes with 13 to 17 pupils fared better than those with 22 to 25 pupils. But neither of these factors influences earning potential as significantly as the standard of teaching that pupils received.
Previous research has shown that poor nursery education was equivalent to - or worse than - no nursery education at all.