How big a population does a local education authority need in order to remain viable? This question is being fiercely debated again following the Local Government Commission's recent recommendation that another 10 English unitary authorities should be established.
The commission says it has never had firm guidelines about the minimum size of unitary authorities - which are taking over the functions of county and district councils - but many local government officers would say that 200, 000 is the preferred minimum.
The 10 proposed authorities (see box) would serve populations of between 120,000 and 240,000. Too small in the English counties' view, but larger than many in Wales.
The counties, of course, stress the importance of size for achieving economies of scale and for the cost-effective delivery of specialist services. Ian Langtry, education officer of the Association of County Councils, says: "The basic problem is how do very small authorities sustain basic services like peripatetic music teachers and consultants for primaries? Except at disproportionate cost, how do they deliver in-service careers development, special needs units with psychologists? Of course they can do it if they have got bags of money."
He points to recent research from Strathclyde University which found that the cost per pupil tended to be lower in larger authorities.
Other sceptics suggest that schools will not have confidence in small unitary authorities and might decide that opting out is a better option. If they do, the unitaries will become even less viable.
If Thurrock in south-west Essex became a unitary authority, for example, it would only have four secondary schools as six have already opted out. More defections would undermine arguments about the advantages of local decision-making because most of the schools' money would be coming from a remote government agency.
Unsurprisingly, the towns and boroughs which want administrative independence think that the size issue is grossly overplayed, pointing out that metropolitan authorities and London boroughs with a population of under 200,000 such as St Helens or Westminster do not have to justify their sizes.
The Association of District Councils' recent report, Reorganisation for real, tackles the size issue by examining small and medium-sized authorities' approach to service-level agreements, special education needs and curriculum advice.
Author Gavin Graveson, an education consultant, described Kingston upon Thames (population: 133,000) as demonstrating that "much may be achieved within even modest resources". Good people are more important than size, he concludes.
The Wrekin, in Shropshire, one of the 10 proposed unitaries, agrees. The authority, which has a national reputation for customer care, is confident that it will be able to deliver a first-class education service.
One of the council's spokesmen said: "Why everyone is so hung up with size I don't know especially in the light of the changing nature of education. It is now about partnerships. It is much easier for us to take an holistic approach because we are closer to our communities. There will be tremendous benefits from linking housing, social services, education, community development, youth services and vocational education and training."