23 March 2012

Will Your Favorite Celebrity Couple Stay Together?

Brain Trust - Source: Random House

Five years ago, Garth Sundem and John Tierney worked together to come up with a mathematical formula to predict which celebrity couples were doomed to split apart.

Five years later, that original equation did an okay, but not great job in predicting which celebrity couples would survive the next five years.

So Sundem and Tierney returned to the drawing board to take advantage of the new data the world had accumulated about the success of celebrity relationships over the previous five years, and have now come up with a new and improved mathematical formula that seems to work better, at least if the backtested results are any indication.

Here's what changed in their own words:

While the 2006 equation did a good job over all of identifying which couples were most likely to divorce, some of the specific predictions proved too pessimistic. Because Demi was so famous — and much more famous than Ashton — we gave their marriage little chance of surviving a year, but they didn't split until 2011. We were similarly bearish on Tom Cruise and Katie Holmes (because of his fame, his two failed marriages and their age gap), but they're still together.

What went right with them — and wrong with our equation? Garth, a self-professed über-geek, has crunched the numbers and discovered a better way to gauge the toxic effects of celebrity. Whereas the old equation measured fame by counting the millions of Google hits, the new equation uses a ratio of two other measures: the number of mentions in The Times divided by mentions in The National Enquirer.

"This is a major improvement in the equation," Garth says.

"It turns out that overall fame doesn't matter as much as the flavor of the fame. It's tabloid fame that dooms you. Sure, Katie Holmes had about 160 Enquirer hits, but she had more than twice as many NYT hits. A high NYT/ENQ ratio also explains why Chelsea Clinton and Kate Middleton have better chances than the Kardashian sisters."

More on the Kardashians later. For now, here's our newest tool, which is based on Sundem and Tierney's new and improved formula for predicting which celebrities are riding on the relationship Titanic.

Celebrity Relationship Factors
Input Data Values
"Good" Fame: Number of search results since 1990 in New York Times archives
"Bad" Fame: Number of search results since 1990 in National Enquirer archives
Husband's Age
Wife's Age
Overexposure: Number of scantily-clad photos among the top five photos returned in a Google image search for the wife's name
Dating: Number of months the celebrity couple dated before getting married
Time: Years after getting married for which to calculate the percentage odds that the couple will still be married.


Odds of Celebrity Marriage Survival
Calculated Results Values
"Good" to "Bad" Fame Ratio
Percentage Chance of Still Being Married After Entered Number of Years

Tierney describes how these factors can influence the outcome of the new formula:

Garth's new analysis shows that it's the wife's fame that really matters. While the husband's NYT/ENQ ratio is mildly predictive, the effect is so much weaker than the wife's that it's not included in the new equation. Nor are some variables from the old equation, like the number of previous marriages and the age gap between husband and wife.

In the fine tradition of Occam's razor, the new equation has fewer variables than the old one. Besides the wife's tabloid fame, the crucial ones are the spouses' combined age (younger couples divorce sooner), the length of the courtship (quicker to wed, quicker to split), and the sex-symbol factor (defined formally as the number of Google hits showing the wife "in clothing designed to elicit libidinous intent").

Now, back to the Kardashians. The default data in the tool above apply to the celebrity coupling of Khloe Kardashian and Lamar Odom, with the results using this default data indicating the probability that the couple will celebrate their 50th wedding anniversary.

And from here, we'll let Garth Sundem describe the results:

"I've calculated the chance of Khloe Kardashian and Lamar Odom celebrating their golden anniversary," he says, "Even when I extend it to 15 decimal places, the probability is still zero."

To be fair, if any of the Kardashians could celebrate a 50th wedding anniversary, it probably would be Khloe. She'll just have to beat some very steep odds to do it though....