In January 1993, Joel Waldfogel asked 86 undergraduate students whether they liked their Christmas gifts. But Waldfogel is an economist, so he phrased the question more precisely, asking them how much they would have paid to buy those items for themselves.

The results were grim, at least for the gift-givers: The students estimated that their gifts had cost $438.20 -- but they said the most they would have been willing to pay for them was $313.40. Two months later, Waldfogel rounded up 58 more students and asked them how much cash it would have taken to make them “indifferent between the gift and the cash.” These students estimated that their holiday gifts had cost $508.90 on average. But they would have been just as happy with $462.10 in cash.

In the resulting paper, “The Deadweight Loss of Christmas,” Waldfogel didn’t pull his punch. “Between a tenth and a third of the value of holiday gifts is destroyed by gift-giving,” he wrote. Generalized across the economy, holiday gift-giving was destroying billions of dollars in value annually.

Santa, Waldfogel estimated, was even worse at helping people than Uncle Sam. “Deadweight losses of in-kind government transfers” -- economist-speak for government programs -- “are thus no larger, and in many cases are smaller, than the deadweight losses of holiday gift-giving.” Economists who are outraged by government inefficiency, he argued, should be similarly appalled at Christmas.

Since publishing his paper 15 years ago, Waldfogel has become the face of the economics profession when it comes to giving gifts. His research has been featured in the New York Times, the Economist, the Financial Times, the Wall Street Journal and many other news media outlets. “Leave it to an economist to make an impassioned argument for why we shouldn’t give gifts, especially during the holidays,” read the Los Angeles Times review of Waldfogel’s 2009 book, “Scroogeonomics: Why You Shouldn’t Buy Presents for the Holidays.”

But it turns out Waldfogel’s is not, as they say in economic forecasting, the consensus view on Christmas. Chicago’s Booth School of Business routinely polls leading economists on the issues of the day. This month, it asked whether “giving specific presents as holiday gifts is inefficient, because recipients could satisfy their preferences much better with cash.” Only 17 percent of the economists agreed. Some 54 percent disagreed. The rest weren’t sure.

Princeton University’s Angus Deaton was one of the economists who disagreed. “This is the sort of narrow view that rightly gives economics a bad name,” he wrote in an accompanying comment.

Reached by phone, Deaton was happy to expand on his thinking. “There’s obviously a point here,” he said. “Money would be better than a gift if you define the problem narrowly enough. And that insight, like a lot of insights in economics, is valuable to have. But stopping there is the problem.”

Yale University’s Judy Chevalier was one of the economists who agreed that giving gifts is inefficient. She even rated her confidence about her answer a perfect 10. But it turned out she actually agreed with Deaton: You can’t stop there. “If you ask people after Christmas how much they value this sweater, it’s almost always less than what the giver spent on it,” she told me. “Does that mean I don’t give Christmas gifts? No, I give Christmas gifts!”

It turns out that there’s a catch to the original Waldfogel thesis: In both surveys, students were specifically instructed not to consider the “sentimental value” of the gifts they received.

But the sentimental value, of course, is often most of the value of the gift. In my house, there’s a gray rock on our coffee table that says “God Bless You” on it. For the most part, I would happily pay someone not to give me a rock with a spiritual inscription. But the rock was a gift from my mother, and so I’ll never part with it. To me, its value is incalculable.

The Waldfogel paper stopped at the cash value of gifts. It wasn’t willing to wade into the murkier waters of sentiment.

None of this is to say that Waldfogel’s insight doesn’t hold important lessons for gift-givers. You have to be a damn good shopper to do a better job spending $25 on someone than they would do spending that $25 themselves. If you’re just buying consumer goods -- a video game or headphones, say -- for someone whose tastes you don’t know that well, you’re probably better off giving cash or a cashlike gift card.

There’s evidence that many gift-givers know this. An interesting finding from Waldfogel’s paper was that gifts from siblings, parents and significant others were rarely or never exchanged, while gifts from aunts and uncles often were. Grandparents, it turned out, are the most thoughtful gift-givers, economically speaking: More than 40 percent of their gifts came in the form of cash.

Gift-givers have an advantage when they know their recipients well enough to give them something they want badly but wouldn’t buy for themselves. This lesson, says Massachusetts Institute of Technology’s David Autor, is validated by behavioral economics, which shows that people are irrationally loss-averse when it comes to money. “There are things you wouldn’t buy for yourself that you wouldn’t give up, once you had them, at their market price,” he says. “So I wouldn’t pay $200 for Beyonce tickets, nor if I had a pair would I sell them for $200.” (I am duty-bound to note that the subject of Autor’s hypothetical here came from me, not him. Whether Autor would give up $200 tickets to the Mrs. Carter World Tour is still an open question.) Gift-givers can do for their friends and family what their friends and family don’t quite have the nerve to do for themselves.

Then, of course, there are the gifts that have sentimental value. Those are the rarest -- in part because they’re the most difficult to find. And as any economist will tell you, the rarer something is, the higher its value.