Diamond Rarity, Engagement Rings, and the Endless Game of Telephone

Sometimes the media seems to be playing an endless game of telephone.

Today, many journalists—myself included—must constantly churn out articles to feed the Internet’s voracious appetite for copy. Often this means rewriting items that have appeared elsewhere. At JCK we generally look for source material, and if possible, interview the people involved. But we can’t always, and on occasion, we draw conclusions we probably shouldn’t, particularly when we follow the herd. (Take this story, for example.)

Bringing this to mind is a press release issued this week by John Hopkins University: “Diamonds May Not Be as Rare as Previously Thought.” Yes, that’s an attention-getting headline, but the subsequent copy couldn’t be clearer:

Diamonds may not be as rare as once believed, but this finding in a new Johns Hopkins University research report won’t mean deep discounts at local jewelry stores.

The report says the results “constitute a new quantitative theory of diamond formation,” but that does not mean it will be easier to find gem-quality diamonds and bring them to market.

For one thing, the prevalence of diamonds near the Earth’s surface–where they can be mined–still depends on relatively rare volcanic magma eruptions that raise them from the depths where they form. For another, the diamonds being considered in these studies are not necessarily the stuff of engagement rings, unless the recipient is equipped with a microscope. Most are only a few microns across and are not visible to the unaided eye.

Most write-ups generally followed that template, even if they included pictures of gems. From there, though, the game of telephone began, and stories appeared that were completely off base.

Morning Ticker wrote, “A new study finds that diamonds are not as rare as jewelers would like you to believe.” World Tech Today said, “A new study throws cold water on anyone who thinks their diamond is incredibly rare gemstone—they’re actually really, really common.” (Really? Where are they?)

The irony is that World Tech Today also reprinted the John Hopkins press release, which completely contradicts what the rest of its article says.

But even notable publications, such as Newsweek, while getting the study right, also referenced the “artificial scarcity” of diamonds, which it says was created by unnamed “big companies” that keep diamond prices high—never mind that prices have been falling all year. (I talk more about the “diamonds are not rare” idea here.)

This isn’t the first time this has happened. Last October, two economics professors at Emory University in Atlanta, Andrew M. Francis and Hugo M. Mialon, published a study, “’A Diamond is Forever’ and Other Fairy Tales,” researching the relation between wedding spending and marriage duration. The study can be found here.

Here is its data on engagement rings:

Spending between $2,000 and $4,000 on an engagement ring is significantly associated with an 8 percent increase in the hazard of divorce in the sample of all persons, while spending less than $500 is associated with an increase in the hazard of divorce in the sample of women.

It concludes that no real correlation exists between wedding or ring spending and marital happiness. That is a valid point, if an obvious one.

The problem is the study is built around a straw man. “The wedding industry,” it says, “has consistently sought to link wedding spending with long-lasting marriages.” Yet the study provides no evidence that the so-called wedding industry ever does that. Bridal magazines, it notes, regularly spotlight lavish weddings. True enough, but the authors don’t demonstrate that those magazines regularly tell readers that a swanky affair leads to eternal happiness. If that were such a pervasive message, they should offer up at least one example.

It also references “A Diamond Is Forever,” the classic De Beers tagline. That clearly links diamonds with love but says nothing about a diamond’s size, the subject of the study. The closest the authors come is the 1990’s-era De Beers tagline, “How else can two months’ salary last forever?” Yes, the two-month salary guideline was terrible, but it hasn’t been used in at least 15 years. Plus, the forever was referring to the diamond. Only an idiot would read that and think, “I’m going to spend two months’ salary on a diamond, and then I will never get divorced.”

But the media coverage was even worse. Just because the study disproves a correlation doesn’t mean it proved its opposite. Subsequent headlines, however, trumpeted that message (even, to some extent, ours). “The bigger your engagement ring, the shorter your marriage,” wrote CBSlocal. “Huge engagement rings show the world you are more likely to divorce,” said Jezebel. “Breaking: Expensive Engagement Rings Lead to Divorce,” proclaimed Cosmopolitan.

As any economist will tell you, correlation does not imply causation. If one assumes, as I do, that no sentient being truly believes that fancy weddings guarantee happiness, the reverse formulation—the amount you spend on your wedding predicts the likelihood of divorce—is equally stupid.

When I tried to clear this up with the study’s two authors, they declined to be interviewed, a rarity for academics. Vox was one of the few media outlets to point out that this study should be “taken with a grain of salt”:

The study is not peer-reviewed. And while it claims to have controlled for “a number of demographic and relationship characteristics,” it never specifies which ones.

But let’s go beyond these instances and others. While the individual writers bear the blame here, the industry is also at fault for not getting its own message out. Information that is not corrected gets repeated. The only way to stop this constant game of telephone is make sure people hear your voice.

JCK News Director