Now that rich people have all the money, they need to develop a social conscience

So there are now 3,300 people in Britain with assets – excluding property – of £5m or more. That, according to the company Datamonitor, which has just produced this estimate, is more than double the number of five years ago.

I don't know whether the figure is right – I would suspect that it is too low – but we do know that there has been a huge increase in wealth over the period, not all of which will have evaporated with the recent fall in the markets. We also know there has been a surge in the numbers of high earners. According to the Inland Revenue, the number of people earning more than £100,000 a year has rising by 50 per cent in four years and now stands at 326,000.

We can see the superficial evidence of wealth all about us, particularly in London and the South-east. The cars, the clothes, the restaurants – these are the visible signs of a lot of money. What we don't see is the deeper social changes that this is starting to bring with it.

This was illustrated recently at a university committee meeting I attended. It was considering alternative sources of finance for one of its units, and the discussion turned to the increasing difficulty of getting money from companies. The days when companies would dish out money to a variety of good causes just because they were good causes was fast disappearing. Boards nowadays had to be very sure that everything they spent could be justified to the shareholders as being of direct benefit to the company. Nowadays, the socialist multi-millionaire opposite pointed out, you went to rich individuals for money, not companies.

That has certainly become the way with political donations. When the Tories or Labour want money (the Lib Dems are not quite so good at it) they go to rich people. It has become a bit embarrassing for a company to admit that it gives money to a political party – it leads to awkward questions from shareholders – but lots of people are perfectly happy to do so. Quite reasonably, if questioned they would argue that it is their money and they can do what they like with it. Politicians, for their part, are happy to use this shift in society: Tony Blair in particular is a genius at deploying the power of his patronage.

What is happening in politics is, I think, an early example of what will happen in society as a whole: a shift of power from institutions to individuals, especially the very rich ones. Companies have to be careful what they do; governments have huge taxing power but also face huge responsibilities which, as society ages, they will find increasingly difficult to honour. Governments, too, will find themselves under the scrutiny of independent auditing, a trend reinforced by Gordon Brown's eagerness to make sure that new public money is well spent. Individuals, however, can reach for their chequebooks, answerable only to themselves.

Those wealthy people will increasingly spend money on things other than material goods. Once people have joined the ranks of the super-rich, which I would define as being able to do more or less whatever they want without having to think about the cost, they tend to spend on what might be called "good causes" – things that make them feel better about themselves.

The obvious model here is the United States, where successful people think of it as normal to use their own money for the public good. Indeed it is rather frowned on not to give money to charity. Of course in the US there are tax advantages in charitable donations, run on a rather simpler system than we have here. But the bigger difference is that the US system, at its best, is designed to use private donations in a more thoughtful and sensitive way than we manage here.

At its best, too, the private sector support for the US system enables it to be more open and egalitarian than we manage to be here. A good example is university education. Harvard's endowment is £12bn, Oxford's less than £2.5bn. So Harvard, despite being a private university, can run a "needs-blind" entry policy. If a student cannot afford the fees, a package of grants, loans and maybe a holiday job is put together to make sure that he or she can take up the place. UK universities have yet to match this. Indeed US universities have gradually become more open to bright students of modest means, while ours are in danger of becoming less open.

If part of the way forward for the UK is to look across the Atlantic and see what we can learn, part is also to look backwards at our own traditions. A century or more ago it was almost normal for someone who had made a bob or two to found a hospital or a school – well, not normal, but not remarkable. But as the state has advanced, the social initiatives of ordinary successful people have been crowded out.

For three generations so much money was taken away by taxation that most people had neither the resources nor the wealth – nor indeed the inclination – to take on wider civil responsibilities. If the state took on the job, why should individuals bother, particularly since their help was often rejected? So they didn't.

We are now in the early stages of reversing all this. The growing numbers of the super-rich form a core of people who can, by deploying not just their wealth but also their knowledge and their contacts, start to make a difference to society. But of course this is not just a job for the fortunate 3,300 or indeed the much larger number of prosperous people who want to put something back. It is a job for everyone who has something to give. Individuals' money or their talent can be applied swiftly and flexibly. Nimble people can plug gaps where the lumbering public sector system fails. People with time and managerial experience can do wonders if given a chance to contribute.

We have the opportunity of shaping how this rebuilding of our society progresses. So far some of the less attractive aspects of the deployment of personal wealth have been more in evidence: the buying of honours, for example. But given time, we will I think see less self-aggrandising and more genuine efforts to help to create a more balanced society. For example, higher education has been squeezed and needs more private money. One friend recently gave a building to his old college, while another has just funded a chair for his university. They don't get much public acclaim for that, nor I think would particularly want it – they want to do the right thing, they happen to been successful in their careers and therefore they are able to help.

This must be the way forward. There will of course be things that only governments can do. But we have become increasingly aware of the limits of government power and the unhappy outcome of well-meaning but badly-constructed state initiatives. There are huge gaps that need to be plugged and they will continue to exist, even assuming greater competence in government. So we have to find ways of involving ourselves, giving time as well as money. But money does matter. Thoughtful, successful and, yes, rich individuals can do things that governments can't.