math214 finally comes in handy

I’ve been trying to get a prank entry under my name removed from IMDB. Thus far the only response I’ve been given is:

The page you are referring to features another person with the same name as you, and as such, is valid and cannot be taken down, sorry.

Let’s just take a look at the odds of that.

This person shares my:

• Full Name (and peculiar shortened first name spelling)
• Birthdate (Day, Month and Year)
• Place of Birth

Ok, so being called “Nik”. What are the odds of that? Well, “Nicholas” is #25 on the most popular male baby names of 2007. And there are only really three possible nicknames (”Nick”, “Nic” and “Nik”). So let’s call that 1 in 100 for “Nicholas” and 1 in 3 for “Nik”. So that’s a 1 in 300 chance of being called “Nicholas” and shortening your name to “Nik”.

What about “Wakelin”? Well, the phone book has 11 people with last name “Wakelin” in Wellington. Let’s be generous and assume the same number of people are unlisted (after all, I am), so that’s 22 “Wakelin”’s in the Wellington Region (pop. 464,700 according to Wikipedia’s 2006 estimate).

Combine the two, and the chances of having my name are about 1 in 10,000,000.

No big deal. Assuming an even name distribution (which is clearly incorrect for a Western-centric name), there would be 660 people calling themselves “Nik Wakelin” around the world (using a July 2007 estimate). It’s not inconceivable that one of those 660 found their way to a part in Shortland Street.

But what about the birthday?

Ok, so there are 365 possible days to be born on. The birthday paradox says it’s basically a given that someone shares the 19th of September with me. But, they’ve got the right birth year too! The average Life Expectancy in Western Countries is about 80 years. So that’s a 1 in 29,200 chance that someone shares my exact birthdate.

Birthplace? Well, we already know that Wellington has a population of 464,700. And given the previous world population of 6,602,224,175, that’s an approximate 1 in 70,000 chance of being born in Wellington, New Zealand.

Combine all three? That’s about a 1 in 20 000 000 000 000 000 that this person is, in fact, someone else who just so happens to share all these details with me.

At those odds, I could have:

• Bowled 1 trillion perfect 300 games
• Been struck by lightning 10 billion times
• Had 109 meteors land on my house

Please take it down, IMDB?

(Note that the above takes incredible liberties with statistics, assumes all variables are independent, ignores variable change, and might be out by a couple zeroes. Even still, the chance is astronomically low)

(The bowling/lightning/meteor stats are based on these odds)