It cannot be money, because teaching has never been well paid, except briefly after the Houghton and Clegg awards, two significant pay settlements in the mid 1970s and early 1980s. In classical times Lucian equated teachers with sellers of kippers in terms of poverty, so nothing new there.

I once reviewed the research on people’s reasons for going into teaching. The two most commonly stated are “wanting to work with children” and “liking my subject”. They are not mutually exclusive and many applicants cite both. There used to be a professor of sociology, who, when told in interview that someone wanted to study sociology to be able to work with people, would reply, “Why don’t you become a masseur then?” In the earlier part of the century more quaint reasons were cited, such as “my parents wanted me to teach”. If your own spotty offspring treat all parental suggestions with the same respect they accord to bird droppings, by the way, you might like to know that this golden age, during which adolescents listened to parents and then obeyed, was in 1934.

When I saw the newspaper headline “Flashy cars for physics teachers”, I did not know whether to laugh or cry.

Universities that used to attract 20 or 30 physics graduates a year to their teacher training courses are now recruiting four or five. The newspaper story reported a proposal that physics graduates should be offered a smart car as an incentive.

At first the proposal sounded demeaning and divisive. Would physicists really rush into teaching, just for a flashy car? I could picture the scene, as some arrogant, freshly recruited physicist roared down the school drive in his new set of wheels like Mr Toad, honking his horn and bawling at cyclists: “Get out of my way, art teacher.” On reflection, however, I wondered whether this crude market-driven idea might be a winner.

There is, at present, no great dearth of history teachers, so it’s Reliant Robins for them, I’m afraid. Primary heads are in short supply, so a nice Mercedes might be in order. For unflappable heads who don’t give a stuff about the Office for Standards in Education a Bentley Mulsanne or Rolls- Royce Corniche could be the answer.

Deputy heads responsible for curriculum and examinations might qualify for a decently nippy BMW 300 series, but the poor beggars given pastoral responsibility for discipline, meeting awkward parents, and toilets that don’t flush, should be offered a top-of the-range BMW 700. In inner-city schools this could be a Chieftain tank.

If material incentives work, then why stop at cars? Devotees who stay after school running extra-curricular activities could be presented with an executive helicopter to take them straight home at the conclusion of arts or sporting events. Skivers, by contrast, who dump responsibilities on colleagues, might be offered a choice between a sub-frontal leucotomy and a stick of dynamite taped to their naughty bits.

The market-driven extrinsic reward systems operating in other jobs might also have an appeal. How about share options? Float the school as a company and then staff could divvy up the profits from the car-boot sale and waste- paper collections, instead of spending it on trivialities such as books and field trips.

Then there was the well-known professional footballer who signed a four-year contract with a large “loyalty bonus” if he stayed the full period. When he left after a year to sign for a richer club, he threatened to take the club to court if they did not give him a quarter of his bonus - for staying loyal for just one season.

With most of the teaching profession having knocked up 20 years or more, you can always demand a loyalty bonus from your school. After all, it’s a dog-eat-dog market out there. If they won’t pay up, take them for every stick of chalk they’ve got.