When Henry Ford first invented the Model T, which rolled off his production lines in Michigan at a staggering rate of one every 24 seconds, he said famously: "The customer can have any colour he wants, so long as it's black." Hunt through the Ford website today, and you find 46 colours on offer (besides black, that is), ranging from toreador red through Oxford white to mocha frost.
What has happened to Ford cars over the past century has happened to lots of other products as well. We are offered what David Lewis, the author of The Soul of the New Consumer, describes as a "glittering haze of choice". Once, Heinz could boast of "57 varieties" of salad cream and other goodies. These days, every self-respecting firm offers 57 varieties of something.
In the past two decades alone, the range of choice has expanded astonishingly. A study in the annual report of the Federal Reserve Bank of Dallas, Texas, compared the choice of food products in 1980 with that of 1998. The choice of breakfast cereals has shot from 34 to 192, it found; of cooking oil from 20 to 161; of paper towels from 11 to 126. Even dogs have unprecedented choice: the number of dog-food brands in the US is up from 58 to 180.
Surely, you might say, choice can go no further. But no. The latest marketing fad, made possible by the combination of the internet and sophisticated databases, is "mass customisation": each consumer can order a completed product different from any other. To see this vision of the future, surf to idtown.com, a watch manufacturer in Hong Kong that offers more than a million permutations of wristwatches.
Nor is it just in what we eat, drink and wear that choice has blossomed. Pick up the latest university admissions handbook and scan the near limitless range of university courses. Flick through the Sunday papers, examining the choice of unit trusts, pension schemes and bank accounts. Look through the job ads at the astonishing variety of skills that employers seek: "I had no idea there were so many different kinds of job in the world," said a baffled friend, recently arrived from a developing country. Only in a few areas of life, such as healthcare, is choice still the privilege of the few, rather than the birthright of the many. Money, as always, buys you more choice in every area of life: but what was once a luxury available only to a few has become democratised. These days, choice is what the mass market provides.
What is the point of so much choice? And does it really make us better off? Most economists have no doubts on this score. Without choice, after all, the market - that exquisite mechanism for delivering myriad goods and services to myriad consumers, each with different circumstances and tastes - cannot exist. One of the most fundamental ideas underlying economics, as Professor Tim Besley of the London School of Economics points out, is that people have different preferences. Forcing people to consume a particular bundle of goods that was the same in all cases would make most of them worse off. "One size fits all" tends, in reality, to be "no size fits anyone".
Fortunately, we have all had a real-world experiment in what happens if people are compelled to accept any colour so long as it's black. It was called communism. By comparing life in East and West Germany at the time of the fall of the Berlin Wall, we can see some of the striking effects of choice: it makes people's lives more fun, more colourful, more convenient. Not only is choice the basis of whole industries - advertising, design, marketing - but it also provides a powerful incentive for companies to devise new products, and is thus one of the drivers of technological advance. Not surprisingly, economists argue that choice is enriching.
But it does not always feel that way. Sometimes choice, like the menu in a Chinese restaurant, seems to deliver more variety than we can cope with. According to Dr Patrick Barwise of the London Business School, when an American household is offered 55 television channels, they watch about 13 of them in a typical week; when offered 90 channels, they still watch about 13. That might suggest a natural limit on the amount of choice people can handle.
We have all had evenings when we flicked away with the remote control and complained that, notwithstanding the number of channels available, there was nothing worth watching on the box. If that is true for this most creative of mediums, surely it will be even more true for the choice of bottled water or baked beans. Some of the options we are offered are more cosmetic than real. The same water may go into both a designer bottle with a swanky brand and a plastic bottle with a plain supermarket label, sold for half the price. The difference is marketing and illusion.
Some choice, of its nature, cannot be about much more than price. Change your supplier of electricity or water, say, and you will not get a stronger current or something more delicious coming out of the kitchen tap. You will get service, with luck, plus a price plan so complex that the people most likely to benefit from the exiguous savings involved will almost certainly find it impossible to understand. Indeed, many choices seem designed to bamboozle and bemuse. Sheila McKechnie, the director of the Consumers' Association, rages against the techniques of "confusion marketing" practised by, for instance, the mobile-telephone companies, whose tariffs are so intricate and diverse that nobody without a PhD in maths has much hope of comparing them. Consumers may have more choice than ever before, but they also tend to have less time: true competition between products is possible only when the price and all the other characteristics are easy to compare.
The result of the plethora of choice is that few people take choices in the way that economists once imagined them doing: carefully weighing up all the costs and benefits, a cold towel wrapped around the temples, assessing all the information and reaching a rational decision. As Patrick Barwise remarks: "No way is that what psychologists mean by rational." Anybody who tried such an economically rational approach to buying a replacement bottle of ketchup "would need help from the men in white coats very soon".
Many choices are taken not rationally, but instinctively. We do things on impulse; we are seduced by first impressions; we may even believe the advertising. Choosing a house, choosing a partner: even life-shaping choices such as these may be made in a few brief seconds, and then endlessly rationalised after the event.
Indeed, we have many sorts of strategies for making choices that are deeply irrational. Often, we use choice to define who we are - what Freud called the "narcissism of small differences". When buying clothes or selecting which newspaper to read, we are often making a statement about how we see ourselves. We may hunt for what Lewis calls "authenticity": wild salmon, not fresh; cold-pressed olive oil, not merely virgin; Islington Farmers' Market, not Sainsbury's. Authentic is rarely less expensive. Lewis recalls a cartoon in the New Yorker in which a designer tells his clients: "Yeah, well, I'm not sure you've got the budget for minimalist."
Where choice is rational, however, we may be too baffled by variety to take the responsibility alone. We search for a guide through the haze. We may telephone a friend or relative. We may locate a trusted guide, as the fashionable phrase has it. No accident that this phrase has cropped up in the context of the electronic media, where a technological revolution is driving forward the possibilities of choice at an unprecedented rate. When people in public broadcasting ponder the future of the BBC, the phrase "trusted guide" is usually on their lips. But there are other such guides already. McKechnie's organisation publishes one. Plenty of people, faced with half a Saturday morning and a dead washing-machine, grab their copy of Which?, scan the list of blobs and simply order the one that fits the bill.
Indeed, one effect of the profusion of choice has been to create whole industries devoted to helping people with decisions. They are insurance salesmen, travel agents, mortgage brokers. Intermediaries are often said to be on the verge of extinction at the hands of the internet. Don't believe it. The multiplication of choice that the internet brings will create more intermediaries, not fewer, although they may not be the same businesses as today's. Most of these, it has to be said, are not trusted guides. Given the well-known reluctance that most people feel about paying for advice, however good, intermediaries make their money from those who sell, not those who buy. They guide you, more often than not, to the product from which they earn the most commission, not the one that, out of thousands, is precisely right for you.
In one large area of life, however, choice is tightly constrained or non-existent: public services. Nobody asks you, if you break your leg, which hospital you want to go to; if your child wants to go to a particular secondary school, you may have to fight through an appeals committee to get there. As choice proliferates in the private sector, so these constraints of the public domain become ever more chafing.
Why do we allow the public sector to take so many decisions on our behalf? Partly, it is to curb costs: spare capacity, essential for true choice in service industries, is expensive to manage and maintain (although private-sector services get better and better at doing so). Public providers cannot use price to influence choices, and direct some consumers away from the desirable towards the unwanted. That is a powerful tool in the market.
Again, many decisions about public services have effects on somebody else: a choice that may seem reasonable if one person takes it becomes impossible if every person wants to do so, as when every family in a town wants to send its children to what everybody thinks is the best school. And public choices are paid for by somebody else, that mysterious nonentity called the "taxpayer", who has hardly any choice about how much cash to hand over to the government.
Governments have a long tradition of not trusting people to choose what is in their best interests, summed up in the deplorable remark by Douglas Jay that, on some matters, "the gentlemen in Whitehall really do know better what is good for the people than the people do themselves". Governments do not much like people choosing things that are bad for them (failing to buckle the seatbelt, say, or taking hard drugs). They also doubt whether people are capable of taking wise decisions about what healthcare they need. Tim Besley, who has spent much of his life in the US, recalls that when he first arrived there, he was bewildered by the idea of choosing healthcare. "I had become an ignorant consumer of healthcare precisely because I had been brought up in a system where choice was not available." Most Americans with a similar educational background were highly in-formed about the choices they had to take. "If you offer people choices, they will often go and acquire the necessary information to do so," he believes. In other words, choice may make people more responsible for the consequences of their actions. It may be a way to develop personal and political maturity.
That helps to explain why there is such a long history of government mistrust of popular choice. Choice is the very essence of democracy: what is an election but an opportunity to throw out one set of rulers and choose another? The rise of special-interest politics, and the fragmentation of party interests that accompanies it, is surely a sort of political parallel to what has been happening in the shops: the decline of big department stores such as Marks & Spencer and C&A, and their replacement by special-interest boutiques such as Jigsaw and Next.
The unpredictability of popular taste has created a strong historical association between choice and social instability. In the Tudor period, according to Don Slater, a sociologist at Goldsmiths College London, writers were fulminating about the way that decadent youth chose flamboyant clothes, made from - shock, horror - imported materials, thus simultaneously undermining British culture and the economy. Three centuries later, says Slater, Alexis de Tocqueville worried that the obsession with individual choice would make people apathetic about the public realm and so undermine the strength of democracy.
An even more durable intellectual tradition, however, associates individual choice with freedom, and with moral strength. To be truly free to make choices requires what the Victorians would have referred to as strength of character, says Jonathan Ree of the University of North London. So choice not only confers moral responsibility; making a choice requires it, if it is to be genuinely free. We all acknowledge this idea whenever we say that children should be denied the freedom of choice that adults take for granted, because, we say, children are not mature enough, not responsible or wise enough.
Perhaps the most alarming aspect of making a choice is our assumption that some choices are bound to be better than others: that there are right decisions and wrong decisions, and that we do not always pick the right.
The l9th-century Danish philosopher Soren Kirkegaard said that, whatever choice a person makes, there will always be others, just as good, perhaps better, which by definition cannot be made. This is the paradox of choice. We talk as if an abundance of choice means we can have it all. In fact, the more choices there are, the more we have to reject. This is where, according to Ree, who borrows the phrase from Kirkegaard, the "anxiety of choice" comes from.
The fear of the road not taken, of the option not explored - that is what frightens us about the big choices in life. We choose one life partner rather than another, and then sometimes look back to that fork in the path; we end up in a career without realising that a gate has swung shut behind us. Making a choice is hard enough, in the babble of information and conflicting signals that surrounds us. But once the choice is taken, and that moment of freedom has passed, we are left with responsibility for our decision.
A burden, yes; but an option that most of us would rather have than be denied. However intolerable a responsibility choice may be, the lack of choice is nearly always more intolerable still.
The writer is on the staff of the Economist. She presents Analysis: 57 Varieties on Radio 4 at 8.30pm on 27 July