What the Bill Predicts

In 2014 two economists at Emory University, Andrew Francis-Tan and Hugo Mialon, released a working paper with a title built to be quoted: A Diamond Is Forever and Other Fairy Tales. It was published the following year in the journal Economic Inquiry. Within days of its release, the headlines had decided what it said: expensive weddings cause divorce.

It said nothing of the kind, and the gap between what it found and what was reported is a good lesson in reading research about relationships.

Start with what they did. They surveyed about three thousand Americans who had ever been married, online, asking about their engagements and weddings: how much the ring cost, how much the wedding cost, how many guests came, whether there was a honeymoon, and whether and when the marriage ended. Then they looked at how those features related to the length of the marriage, taking account of a range of characteristics such as age, income and education.

Here is what they found. Higher spending on the engagement ring and on the wedding was associated with shorter marriages, at least in some ranges. In the figures that were most widely reported, men who spent between two and four thousand dollars on a ring had a hazard of divorce about 1.3 times that of men who spent between five hundred and two thousand, and women whose weddings cost twenty thousand dollars or more had a hazard about 1.6 times that of women whose weddings cost between five and ten thousand. A large number of guests and having a honeymoon were both associated with longer marriages.

Now what it could not show.

This is a correlational study. It compares couples who made different choices; it does not assign couples to spend different amounts and then watch what happens. That matters because the couples who spend heavily are not a random sample of couples. They may be more likely to have borrowed to pay for the day, and money strain is a well-documented source of conflict in marriages. They may differ in age, income or background in ways the statistical adjustments only partly capture. They may include couples who wanted the occasion to say something the relationship did not yet say on its own. Any of those could produce the association without the spending causing anything.

The sample has limits too. An online survey of volunteers is not a random draw from the population, the spending figures were remembered years after the event, and one survey is one survey. The authors were explicit that their results did not establish causation. Much of the coverage reported that caution in its last paragraph, after the headline had done its work.

The guest-count finding deserves the same scepticism in the opposite direction. A couple with two hundred people who want to come to their wedding has a large network of family and friends, and a network may help hold a marriage together. The guests are evidence of the network, not its cause, and nobody should conclude that inviting more people makes a marriage last. The honeymoon may be similar: couples who can take one may differ in time, money or circumstances from couples who cannot.

So what does survive?

Something narrower than the headline, and more useful. The wedding industry runs on an implied claim: that the scale of the celebration expresses the depth of the commitment, so that spending more is a way of taking the marriage seriously. On that claim the evidence is not ambiguous. Nothing in this study, or anywhere else, shows that a bigger budget buys a longer marriage, and the association that does exist runs the other way.

A note on the numbers you will be quoted. Industry surveys in the 2020s have put the average American wedding at around thirty thousand dollars. Those surveys are usually answered by users of wedding-planning websites, who are more invested in the event than the average couple, and they report the mean, which a minority of very expensive weddings pulls upward. The typical couple spends less than the headline figure, which is worth knowing when the headline is being used to tell you what is normal.

The honest summary fits in two sentences. Nobody has shown that a cheap wedding saves a marriage. Nobody has shown that a costly one helps.