# Man Calculates Number Of Suitable Partners In London

By M@ Last edited 173 months ago

Last Updated 14 January 2010

Man Calculates Number Of Suitable Partners In London

Economics lecturer Peter Backus has used a famous equation for enumerating alien civilisations to calculate his chances of finding the perfect girlfriend. They're not good. Despite his hedonistic surname, Mr Backus can only expect to find 26 women in the whole of London who match up to his exacting standards. Let's examine his working.

His calculation is based on the Drake Equation, which famously estimates the number of contactable civilisations in our galaxy:

N = R* x Fp x Ne x Fi x Fc x L

Although the numbats at the Telegraph find it 'baffling', the formula is actually very simple, including terms for the fraction of stars with planets (Fp), the fraction of those that develop life (Ne) and the fraction of those with intelligent life (Fi). All fairly intuitive. Mr Backus has reimagined the terms to suit his own amorous ambitions thus:

N = The number of potential girlfriends.

R* = The rate of formation of people in the UK (i.e. population growth).

Fw = The fraction of people in the UK who are women.

fL = The fraction of women in the UK who live in London.

fA = The fraction of the women in London who are age-appropriate.

fU = The fraction of age-appropriate women in London with a university education.

fB = The fraction of university educated, age-appropriate women in London who I find physically attractive.

L = The length of time in years that I have been alive thus making an encounter with a potential girlfriend possible.

(See his original 'paper' for values of these terms, and context.)

His conclusion?

That on any given night out in London, there is a 0.0014% chance that he'll meet an appropriate partner, even less if he factors in vagaries such as whether they'll get on or not. Now, there are any number of reasons why his calculation is shaky (for example, it assumes random mingling, whereas he's more likely to attend events with similar kinds of people). But the paper is fun to read through for anyone with nerdish tendencies. And it's refreshing to see a 'boffin creates formula' story that isn't tied into an advertising campaign for some related product.

Image from xkcd, reproduced under Creative Commons license.