The Tory party seminar on its future arts policy last month threatened to be a great deal less fun without Boris Johnson, who managed to get himself kicked onto the back benches one day before the event.

As it turned out it was less of a policy announcement and more of a talk on aspects of arts policy: tax breaks for giving art, artefacts and money and generally encouraging a culture of giving.

The Tories are not alone in their enthusiasm for private giving, although the idea that they favour forms of funding that are less to do with direct government subsidy, and more to do with subsidies via tax breaks on donations of cash or objects, is probably no great surprise.

The Tories have always favoured the US system of funding-by-donation. But they have never gone so far as the Americans in introducing the tax sweeteners that are a substitute for direct government subsidy in the US. Labour has also seemed keen to encourage giving.

The Treasury asked Sir Nicholas Goodison to look into the giving of objects to museums and his report was published this January, but we are waiting for the results of the comprehensive spending review, hopefully in the next week or so, to see if the Treasury will respond positively to his recommendations.

Encouraging people to donate has become increasingly important to museums - from the most recent, high profile donations of artworks by artists to the Tate, to the donors, big and small, that have supported lottery projects, and the enthusiasts that help to keep many independent museums alive.

Only last month, the Royal Museum in Scotland announced a programme of renewal costing more than £70m, which will need at least some input from private donors. Glasgow set up a special fundraising unit to support the refurbishment of Kelvingrove: now it has announced a Zaha Hadid-designed solution to its transport museum, even more private support is likely to be needed.

The same trend is emerging in continental Europe, which long-resisted sources of funding to museums other than that of the state. Since 2003 in France, tax breaks have been offered to companies that buy art for museums, and it is likely that individual giving will be the next thing to move on to as corporate sponsorship becomes more competitive.

And yet in the UK the culture of giving is, if anything, in decline despite the generosity of the Ondaatjes, Sainsburys and Clores.

In the UK, only 1 per cent of GDP is given by the public to charity, less than half the amount that is given in the US. According to new research by the Charities Aid Foundation and the National Council for Voluntary Organisations, giving has fallen by 25 per cent relative to GDP over the past decade.

This is despite the fact that the rise in house prices has made many more people better off. And the rich are the biggest culprits of the lot: the top 10 per cent give less than 1 per cent of household expenditure, while the poorest 10 per cent give more like 3 per cent.

The truth is that we may not want an American-style subsidy-through-tax-break system, but we would certainly do better if the rich of Britain embraced a US-style version of social philanthropy.

Jane Morris, editor