Shared heads - a step too far?

As I was driving home earlier tonight a headline on the news captured my attention. Borders Council has decided that, in order to save money, among other measures, it will reduce the number of Headteacher posts. In future, it is proposed, schools will share heads. I am a keen supporter of sharing leadership but is this approach to leadership based on sound business and educational principles or is it driven by a need to cut costs?

''Our new structures as they evolve and settle down will provide schools with greater development capacity.

"This will help us build on our strengths and enable us to maximise on the benefits from the Curriculum for Excellence."

''... the controversial proposal for shared headships could operate successfully but needed to be "monitored and managed effectively".

How many more people will be employed to monitor and manage headteachers? Where is the evidence that supports the move for sharing headteachers across schools as being an effective one for pupils? Does a model of sharing heads across schools actually deliver the goods?