why do schools in Northern Ireland seem routinely to outperform their counterparts from England and Wales?
This is one question that this month's GCSE and A-level results have prompted. The results reveal a striking disparity in the average achievements of pupils from the two places at least in the most often-quoted measures.
At GCSE, 72 per cent of Northern Irish entries gained a C or above, compared with 63 per cent in both England and Wales, while a quarter of grades in Ulster were A* or A, compared with 19 per cent in England and Wales.
The difference is even more stark at A-level, particularly the proportion achieving A grades. In Northern Ireland, a third (33 per cent) were awarded the top grade compared with a quarter in England (25 per cent) and Wales (24 per cent).
These figures should come as no surprise, since Northern Ireland's lead has been established over many years.
Some commentators have attributed the province's success to the fact that it is the only area of the UK to have retained a system of grammar schools. But is this a fair assessment? Certainly, it is not a universal view. Teachers and academics who spoke to The TES said other aspects of schooling in Northern Ireland gave it an advantage. Principal among these would appear to be the virtual absence of teacher shortages.
Risteard MacDaibheid, an award-winning teacher and vice-principal of Gaelscoil Eadain Mhoir in Derry and an opponent of the 11-plus, said: "There's much more hunger for jobs over here. Often there are 60 or 70 people applying for one post, which means you are going to get the best teachers, so it's not surprising that results are better."
Professor John Howson, the teacher recruitment expert, said that Northern Ireland had always had a ready supply of new recruits.
"I think it's pretty clear that where you have a settled teaching force and high quality applicants, these are the things that can make a difference to results," he said.
Traditionally, compared with Northern Ireland, graduates in England have enjoyed a greater choice of careers other than teaching because of the relative strengths of the economy, said Professor Howson. Poorer employment prospects for the less well-qualified might also be what helps to motivate Northern Irish pupils.
Frank Bunting, of the Irish National Teachers' Organisation, said: "The lack of jobs has been a factor. People perceive that to get into employment you need to be well-qualified, so there is a big incentive to do well at school."
Supporters of grammar schools, however, have some evidence in their favour beyond a simple comparison of pupils' relative performance. A recent study by academics at the London School of Economics and the Paris-Jourdan Sciences Economiques found that Northern Ireland's lead over England became well established after its grammar school sector expanded dramatically in the 1980s.
The 11-plus is scheduled to be phased out next year in Northern Ireland, although the prospects of that happening depend on Ian Paisley's Democratic Unionist Party and Sinn Fein reaching agreement on the subject a prospect that currently seems remote.