MEET AN economist who is about to make sense of your entire adolescence.
Kai Konrad is a specialist in public debt. But 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 will bring back memories. I am thinking about Phil Collins right now. He used to sing about "easy lovers".
Konrad calls them "high-frequency daters". Pat Benatar - who sang Love is a Battlefield - 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 to describe them, and they are not nice.
As he sees it, it is a problem of missed communication.
Konrad 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.
But high-frequency daters quite like shopping around, and they are in no hurry.
When high-frequency daters meet other high-frequency daters, there is no problem. They have a good time and probably move on.
When low-frequency daters meet low-frequency daters, there need not be a problem either. They might even marry. Although given they are so cautious about exposing their feelings, they might quite likely never meet.
The problem arises when a low-frequency dater meets a high-frequency dater and does not know it. They can tell the high-frequency dater is interested, but cannot tell whether or not it is because the person is nearly always interested (an "easy lover") or is similarly cautious and genuinely finds them extraordinary.
If it is the second, marriage is highly likely. If it is the first, there is Buckley's chance.
Konrad's calculations show easy lovers turn out to be cautious marriers. As he puts it, they have "high reservation utilities for entering into marriage". Stripped of the maths, the reasoning is straightforward. High-frequency daters hook up with so many potential lifetime partners they can "afford to be picky". This makes them heartbreakers. Without meaning to, they hurt cautious daters, who mistake their passing interest for something serious.
As Konrad puts it, somewhat technically: "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 is gracious enough not to list the descriptions given to women, merely saying they are "labels that receive similarly low social approval".
The labels sound like moral judgments, but Konrad thinks that is not where they are coming from. Society comes up with hateful words for easy lovers 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 "pizazz". They thought it was a 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 were less so.
Konrad disagrees. He thinks it is more of a matching process. What is important for some is unimportant for others.
German economists Arnaud Dupuy and Alfred Galichon last year examined 20 years of social and marriage data and came to more or less the same conclusion. Some things do matter, big time. But for others, it is simply a matter of taste.
Education really matters. Dupuy and Galichon find it is twice as important as height or body mass index. All types of women find a more 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, but only to women who are "conscientious", men with "autonomy" are attractive to women who are extroverts but repellent to women who are conscientious, and so on.
What makes a marriage stay together? One third of them do not. Examining 2480 Australian marriages over seven years, Rebecca Kippen of Melbourne University and Bruce Chapman of the Australian National University found it helps enormously if the couple are close in age and are similarly educated.
Nothing much else matters, or at least nothing much else that economists can get at.
Perhaps some of it is meant to be mysterious.