"When high-frequency daters meet high-frequency daters, there's no problem."

"When high-frequency daters meet high-frequency daters, there's no problem." Photo: Karen Neumann

Meet an economist who's about to make sense of your entire adolescence.

Kai Konrad is a specialist in public debt. In a departure from his normal role at the Max Planck Institute for Tax Law and Public Finance in Germany, he has just published a paper titled Affection, speed dating and heart breaking.

It'll bring back memories. I am thinking about Phil Collins. He used to sing about ''easy lovers''. Konrad calls them ''high-frequency daters''. Pat Benatar would have called them ''heartbreakers''. But why? Why do ''easy lovers'' cause so much heartbreak and why does so much of society think badly of them?

Konrad lists some of the words used, and they are not nice.

As he sees it, it's a problem of missed communication. He says there are two types of daters. Low-frequency daters find the process emotionally exhausting. They are more interested in finding ''the one'' than in shopping around. High-frequency daters quite like shopping around. They are in no hurry.

When high-frequency daters meet high-frequency daters, there's no problem. They have a good time and (probably) move on. When low-frequency daters meet low-frequency daters, there needn't be a problem either. They might even marry (although given that they are so cautious about exposing their feelings, they might never meet).

The problem arises when a low-frequency dater meets a high-frequency dater and doesn't know it. He or she can tell that the high-frequency dater is interested, but can't tell whether or not it is because that person is nearly always interested (an ''easy lover'') or similarly cautious and genuinely finds him or her extraordinary.

If it's the second, marriage is highly likely. If it's the first, there's Buckley's chance. Konrad's calculations show easy lovers turn out to be cautious marriers. They have ''high reservation utilities for entering into a marriage'', he says.

Stripped of the maths, the reasoning is straightforward. High-frequency daters hook up with so many potential lifetime partners that they can ''afford to be picky''. This makes them ''heartbreakers''. Without meaning to, they hurt cautious daters who mistake their interest for something serious.

As Konrad puts it, ''High-frequency daters have a negative externality for low-frequency daters. Their higher fall-back utilities as players participating in the matching process make them more reluctant to propose. As a result, if people of different matching frequency meet, the high-frequency dater is more likely to disappoint the low-frequency dater.''

Disappointment turns to anger. Konrad lists several of the labels given to such men: womaniser, playboy, etc. He does not list those given to women, merely saying they are ''labels that receive similarly low social approval''.

The labels sound like moral judgments, but Konrad thinks that's not where they are coming from. Society comes up with hateful words for easy lovers simply because they unintentionally disrupt the marriage market.

What are people in the market looking for when it is working well? Economists used to call it ''pizzazz''. They thought it was one single property made up of things such as beauty, height, earning power and the like. Those who had more of it were more marriageable, those who had less, less so. Konrad disagrees. He thinks it is more of a matching process. What's important for some is unimportant for others.

Last year, German economists Arnaud Dupuy and Alfred Galichon examined 20 years of social and marriage data and came to the same conclusion. Some things do matter, but for others, it's a matter of taste.

Education matters. Dupuy and Galichon find it's twice as important as height or body-mass index. All types of women find an educated man more attractive, but only some types of men find an educated woman attractive. After that it gets messy. Emotionally stable men are attractive to ''conscientious'' women. Men with ''autonomy'' are attractive to extroverts but repellent to conscientious women.

What makes a marriage last?

One-third don't. Examining 2480 Australian marriages over seven years, Rebecca Kippen, of Melbourne University, and Bruce Chapman, of the Australian National University, found it helps greatly if the couples are close in age and similarly educated. Nothing much else matters, or at least nothing economists can get at. Perhaps some of it is meant to be mysterious.

Twitter: @1petermartin