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It’s time to dispose of an age-old question. Do people spend their lives looking for “the one”, the person – or, less ambitiously, a particular type of person – who is the perfect match for them temperamentally, socially, professionally, financially and sexually? Or do people adjust their standards depending on what they can get? In other words, are the romantics right or the cynics?

I’ll admit that I can’t answer that question definitively – not even the most ingenious of today’s new generation of economists have devised an experiment that will prove whether people lower their sights in response to market conditions when it comes to marriage. But there is some suggestive evidence from the study of speed-dating, courtesy of the economists Michèle Belot and Marco Francesconi.

Speed-daters are able to propose to anyone and everyone they meet, and do so electronically after the event, so that the embarrassment of rejection is minimised. That should mean that, for most people, a proposal of a date is a simple, uncomplicated expression of approval and that nobody would propose a date they didn’t want accepted or hold back a proposal even though they wanted a date. Belot and Francesconi persuaded one of Britain’s largest dating agencies to release information about the activities of 1,800 men and 1,800 women who, over nearly two years, attended 84 speed-dating events. The researchers were able to see who went to which event, and who proposed to whom. It won’t surprise many people to hear that while women proposed a match to about one man in ten they met, men were a bit less choosy and proposed a match to twice as many women, with about half the success rate. Nor will it shock anyone to hear that tall men, slim women, nonsmokers and professionals received more offers. But what might raise the odd eyebrow is that it became clear from about 2,000 separate speed-dates (that’s 100 hours of stilted conversation) that people seemed systematically – and rationally – to change their standards depending on who showed up for the speed-date. They didn’t seem to be looking for “the one” at all.

For example, men prefer women who are not overweight. You might think, then, that if on a particular evening twice as many overweight women as usual show up, it will be a night where fewer men propose. Not at all. The men propose just as frequently, so that when twice as many overweight women turn up, twice as many overweight women receive offers of a date.

Similarly, more women prefer tall men than short men, but on evenings where nobody is over 6ft, the short guys have a lot more luck. Most people prefer an educated partner, but they will propose to school dropouts if the PhDs stay away. If people really are looking for a partner of a particular type, we would expect them to respond to the absence of such people by getting the bus home with a disappointed shrug, resigning themselves to spending Saturday night in front of the TV, and hoping for a better turnout at the next speed date. But that isn’t what happens. Instead, people respond to slim pickings by lowering their standards.

Note that this experiment doesn’t suggest that people aren’t fussy: even the men turn down 80 per cent of the women, and the women are choosier still. What it does show is that we are fussier when we can afford to be and less so when we can’t: crudely speaking, when it comes to the dating market, we settle for what we can get.

Francesconi told me that, according to his estimates, our offers to date a smoker or a non-smoker are 98 per cent a response to – there’s no nice way to put this – “market conditions” and just 2 per cent governed by immutable desires. Proposals to tall, short, fat, thin, professional, clerical, educated or uneducated people are all more than nine-tenths governed by what’s on offer that night.

Only when there is an age mismatch do people even seem to consider waiting for another evening and hoping for a more suitable range of potential mates. Even then, the importance of preferences is still less than the importance of the market opportunity. In the battle between the cynics and the romantics, the cynics win hands down. “Who you propose a date to is largely a function of who happens to be sitting in front of you,” Francesconi explained to me. (He is a charming Italian who I imagine would do rather well if forced to participate in a speed date.) “In this case, that is largely random.” Now, of course, the fact that people seem happy to settle for what they can get when contemplating asking someone for a date next Saturday doesn’t prove that their standards are equally malleable when it comes to contemplating marriage. But we choose our first dates from among the people we meet, and we choose our marriage partner from among the people we’ve been on dates with. Moreover, if you turn down everybody on the marriage market, you’re going to die alone; if you turn down everybody on the speed-dating market on a particular evening, you get to try again in a few days, and the organisers will even pay for it. (People who make no proposals get a courtesy invitation to another speed date.)

If our standards for marriage are as inflexible as a romantic might like to believe, why do they become so stretchy on a speed date, given that the cost of maintaining those standards is so low? My suspicion is that since we adjust to conditions when dating, we also adjust to conditions in longer-term relationships.

That may be enough to put you off the economists’ analysis of dating and marriage already, but I hope not. Yes, economists think of dating and marriage as taking place in a “marriage market”, but that does not mean a market where husbands and wives are bought and sold. It simply means that there’s a supply, there’s a demand and, inevitably, there is competition. None of this is to deny that true love exists. But while love is blind, lovers are not: they are well aware of what opportunities lie ahead of them and they rationally take those opportunities into account when they are dating. They also make big, rational decisions to improve their prospects, or to cope when prospects look grim. Supply and demand in the dating market motivates people to work, to study and even to move in search of better prospects.

© Tim Harford 2008

Extracted from The Logic of Life: Uncovering the New Economics of Everything published by Little Brown on February 7, £18.99. Available from Times BooksFirst at £17.10, free p&p. 0870 1608080

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