Caution: gift horses in transit

Never look a gift horse in the mouth, they say.

Never look a gift horse in the mouth, they say. Really? Never? Do they have any idea how much it costs to stable a horse? Or of how ruinous the vet's bills can be for a beast with health-threatening teeth? The proverb presupposes that gifts cost the recipient nothing, whereas the truth is that you always pay for a present in one way or another. And if this sounds hideously Scrooge-like, I'm not for a moment arguing that you can never graciously accept a gift, or accept it as evidence of human selflessness. Just that it's as well to be aware of the reciprocal obligations that it may entail; at the very least, you're less likely to end up being accused of ingratitude.

So, when I read about the fact that the Tate had been given, or promised, artworks by many of Britain's leading contemporary artists, my first thought was that this was a Lipizzaner stallion of a gift horse, and the second was that it might be worth peeling back the lips and checking the dentistry anyway.

On the face of it, it's true, the Tate apparently has nothing to lose - filling out the gaps in its collection in a way that it would otherwise find it very difficult to do. The problem for the gallery is that it finds itself in a market bubble it has partly helped to create. As Sir Nicholas Serota explained, the purchasing power of the Tate's acquisition fund has been badly hit by art-price inflation, and stands at just five per cent of what it was 20 years ago.

In 1980 the gallery could successfully bid for an Andy Warhol diptych of Marilyn Monroe and still have lots of cash left over. But had they decided that they had to acquire The Fragile Truth - one of the works in Sotheby's recent sale of Damien Hirst restaurant fittings, and a piece that eventually established an auction record for the artist (£1,237,600) - they would have pretty much blown their annual budget in one go. That's mad money, and the gallery simply doesn't have it any more.

I'm not myself convinced that this is entirely a bad thing. Why fund a public gallery to help ramp up prices on the international art market and make the bubble even bigger and more insubstantial than it already is? Sometimes it's just not a good time to buy. And unless you believe that prices will rise in perpetuity, with no future correction to the market, you might conclude that having your acquisitive instincts curbed by penury could be a blessing in disguise. If you really want a Hirst, wait for another 20 years when you may well find he's surprisingly affordable compared to today's prices - or bend his ear for one he's got going spare.

You might also wonder a little about the notion of the "representative collection" which underlies this arrangement. Personally I wouldn't be quibbling if David Hockney, Anthony Gormley, Anish Kapoor and Paula Rego offered to give me a freebie (I'd even settle for a loaner, if they felt so inclined). But there are art-works that would probably end up at the back of the airing cupboard, along with unwanted wedding presents.

And what if, just for the sake of argument, we're not passing through a high-water mark in British culture but a period that will come to be seen as of only scholarly interest to future generations? An art historian would probably want mediocrity to be represented as comprehensively as excellence, but it would still be a bad idea to pay over the odds for it.

In the long term the gift scheme gets round that problem rather effectively. If, in 40 or 50 years, the work doesn't look quite as alluring as it does now, it can presumably be quietly put away in store - along with all the Tate's other former heroes.

In the short term, though, you can't help wondering about how the generosity of artists is to be policed. According to one report the Tate hopes that the scheme will become a "fashionable bandwagon". Not their phrase, I think, but still a reminder that access to the vehicle is going to be a ticket-only affair. One assumes, for instance, that if Jack Vettriano rang up offering one of his canvasses to the gallery his gift would be brusquely declined.

The truth is, for all Sir Nicholas's courteous remarks about the generosity and selflessness of the artistic donors, that the giver has something to gain as well as the recipient. It's not hard to imagine some awkward moments in the future, when the donor's notion of the value of a gift doesn't quite match up to the recipient's. In the end, to be honest, the teeth look pretty sound, even to someone as churlishly suspicious as me. But, contrary to the folk wisdom, it's always worth checking them out.