What Are the Chances – Don't Ask.

August 6, 2009
Posted by Jay Livingston

No doubt others will be blogging today’s NY Times story, “For Today’s Graduate, Just One Word: Statistics .”

I probably shouldn’t be saying this on the eve of the ASA, but there are times when statistical, sociological thinking is, well, not wrong, but not quite appropriate. Several months ago, on This American Life, a man told of something that happened early in a romantic relationship. I don’t remember anything about him, except that he was some sort of scientist, or at least he looked at the world in a scientific way.

He and his girlfriend, were talking about “how great it was that we were in love and that we’d found each other, it felt so ‘fated.’ And she asked, ‘Do you really think we were the only one for each other?’” He did some quick mental calculations and figured that out of the six billion people on the planet, the number of girls that he could have matched up so well with would have to be a fairly small number – a teeny tiny fraction of a percent.

“And I said, ‘I don’t know if you’re the only one for me, but I think that you have to be at least one in a hundred thousand.”*

It was their first big fight.

Or as Tim Minchin sings,

Your love is one in a million
You couldn’t buy it at any price
But of the 9 point 9 hundred thousand other loves,
Statistically some of them would be equally nice.

It's just mathematically unlikely
that at a university in Perth
I happened to stumble on
the one girl on earth
specifically designed for me

It’s from his song “If I Didn’t Have You,” which Kieran posted a couple of months ago. In case you missed it then, here it is.

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* For the record, 100,000 out of six billion is 17 one-thousandths of a percent. Even adjusted for sex and age, it will be a small fraction of a percent.