Economic Naturalist Question #2: Why do brides often spend thousands of dollars on wedding dresses they will never wear again, while grooms typically rent cheap tuxedos, even though they will have many future occasions that call for one?

Jennifer Dulski, who got married six months before she took my class in 1997, posed one of my all-time favorite responses to my Economic Naturalist writing assignment.

Asking why brides buy and grooms rent is an interesting question because it would seem that each would do better by following the other’s strategy. Why don’t brides rent and grooms buy?

Ms. Dulski’s answer began with a strong assumption--that on important social occasions, making a favorable fashion statement matters more to women than to men. I have discussed her example in many different countries and have not met anyone who quarreled with that assumption.

To enable brides to make a fashion statement in a rented gown, a rental company would have to carry a huge inventory of distinctive gowns—perhaps fifty in each size. Each gown would thus be rented only infrequently, perhaps just once every five years.

The company would have to charge a rental fee greater than the purchase price of the garment just to cover its costs. And since buying it would be cheaper, no one would rent.

In contrast, because grooms are willing to settle for a standard style, a rental company can serve this market with an inventory of only two or three tuxedos in each size.

So each suit gets rented several times a year, enabling a rental fee that is only a fraction of its purchase price—an attractive offer if cash is tight.

The rise of internet commerce in the years since Ms. Dulski took my course affirms the appeal of her argument.

As Adam Smith recognized, specialization is limited by the extent of the market. Widespread internet access combined with dramatically lower shipping costs have now made possible a nationwide market in rental gowns.

With a large inventory to choose from at reasonable prices, a growing number of brides are now in fact renting their wedding gowns online. But for the reasons Ms. Dulski described, such rentals wouldn't have been practical in 1997.