Economics has long been known as an unpleasant science. But is any economist so dull as to

Economics has long been known as an unpleasant science. But is any economist so dull as to criticize Christmas? At first glance, the holiday season in western economies seems a treat for those who are concerned with such things as GDP growth. After all, everyone is spending; in America, sellers 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's thinking of something that the receiver 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 often done badly. Every year, ties go unworn and books unread. And even if a gift is enjoyed, it may not be what the receiver would have bought if they had spent the money themselves.
Interested in this mismatch between wants and gifts, in 1993 Joel Waldfogel, then an economist at Yale University, attempted to estimate the disparity(差距) in dollar terms. 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 emotional value of the items, if you did not have them, how much would you be willing to pay to get them? His results were unpleasant: on average, a gift was valued by the receiver well below the price paid by the giver.
The most conservative(保守的) 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 avoided without making anyone poorer. In other words, if the giver gave the cash value of the purchase instead of the gift itself, the receiver could then buy what she really wants and be better off for no extra cost. 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 call for an end to gift giving, or at least press for money to bee the gift of choice?
56. Why do some people regard the holiday season in western economies a treat?
A. Because the economic situation in US has been depressing.
B. Because American sellers make a quarter of their yearly sales through holiday season.
C. Because holiday spending can speed up GDP growth.
D. Because sellers can make as much profit as 60 % over holiday season.
57. What's the main idea for the second paragraph?
A. In many cases the gifts cannot meet the receivers’ needs.
B. The purchases made over holiday season are actually a waste of money.
C. It's really not easy to guess the others’ preferences.
D. Much of the holiday spending is on gifts for others.
58. The purpose of Joel Waldfogel's study is to     .
A. prove the mismatch between wants and gifts
B. estimate the disparity between wants and gifts in economic terms
C. spark new ideas of economic studies on holiday spending
D. discover the exact cost of holiday spending on gift giving 
59. Economists think of the misusing 10% of holiday spending as a deadweight loss because
    .
A. the cash value of the purchase is lower than the buying price
B. it is actually a waste of resources in economic terms
C. with the money the receivers can be better off for no extra cost
D. it makes many people even poorer for spending more on unwanted gifts
60. According to the passage altogether how much money is wasted every year on gift giving?
A. About $4 billion.                                  B. About 10% of the total value.
C. About $40 billion.                              D. Much more than $4 billion.C