Economics has long been known as the dismal science. But is any economist so dreary as to

criticize Christmas？ At first glance, the holiday season in western economies seems a treat for those concerned with such vagaries as GDP growth. After all, everyone is spending; in America, retailers make 25% of their yearly sales and 60% of their profits between Thanksgiving and Christmas. Even so, economists find something to worry about in the nature of the purchases being made.

Much of the holiday spending is on gifts for others. At the simplest level, giving gifts involves the giver thinking of something that the recipient would like—he tries to guess her preferences, as economists say—and then buying the gift and delivering it. Yet this guessing of preferences is no mean feat; indeed, it is often done badly. Every year, ties go unworn and books unread. And even if a gift is enjoyed, it may not be what the recipient would have bought had they spent the money themselves. Intrigued by this mismatch between wants and gifts, in 1993 Joel Waldfogel, then an economist at Yale University, sought to estimate the disparity in dollar terms. In a paper that has proved seminal in the literature on the issue, he asked students two questions at the end of a holiday season: first, estimate the total amount paid (by the givers) for all the holiday gifts you received; second, apart from the sentimental value of the items, if you did not have them, how much would you be willing to pay to get them？ His results were gloomy: on average, a gift was valued by the recipient well below the price paid by the giver. The most conservative estimate put the average receiver's valuation at 90% of the buying price. The missing 10% is what economists call a deadweight loss: a waste of resources that could be averted without making anyone worse off. In other words, if the giver gave the cash value of the purchase instead of the gift itself, the recipient could then buy what she really wants, and be better off for no extra cost. If the results are generalized, a waste of one dollar in ten represents a huge aggregate loss to society. It suggests that in America, where givers spend $40 billion on Christmas gifts, $4 billion is being lost annually in the process of gift-giving. Add in birthdays, weddings and non-Christian occasions, and the figure would balloon. So should economists advocate an end to gift-giving, or at least press for money to become the gift of choice？

Why do some people regard the holiday season in western economies a treat？

A．Because the economic situation in US has been gloomy.

B．Because holiday spending can stimulate GDP growth.

C．Because American retailers make a quarter of their yearly sales through holiday season

D．Because retailers can make as much profit as 60% over holiday season.