Not everyone agrees with this. The article Christmas gift giving: a deadweight loss? from Business World mentions:
"the process of gift giving adds value to a gift over and above its retail price. Giving a gift instead of cash says the giver bothered to know what the receiver might want. There are times, in fact, when gifts that weren’t wished for turn out to be most valued. A thing one would not have thought of buying himself might end up a pleasant surprise. Or, an item the recipient might have had money to spend on but never bought for frugal reasons could also turn out to be a gift valued more than its price."
An article from the Economist magazine, "Is Santa a deadweight loss?: Are all those Christmas gifts just a waste of resources?, raised the question "So should economists advocate an end to gift-giving?" Here is the answer they provided:
"There are a number of reasons to think not. First, recipients may not know their own preferences very well. Some of the best gifts, after all, are the unexpected items that you would never have thought of buying, but which turn out to be especially well picked. And preferences can change. So by giving a jazz CD, for example, the giver may be encouraging the recipient to enjoy something that was shunned before. This, and a desire to build skills, is presumably the hope held by the many parents who ignore their children's pleas for video games and buy them books instead.
Second, the giver may have access to items—because of travel or an employee discount, for example—that the recipient does not know existed, cannot buy, or can only buy at a higher price. Finally, there are items that a recipient would like to receive but not purchase. If someone else buys them, however, they can be enjoyed guilt-free. This might explain the high volume of chocolate that changes hands over the holidays.
But there is a more powerful argument for gift-giving, deliberately ignored by most surveys. Gift-giving, some economists think, is a process that adds value to an item over and above what it would otherwise be worth to the recipient. Intuition backs this up, of course. A gift's worth is not only a function of its price, but also of the giver and the circumstances in which it is given.
Hence a wedding ring is more valuable to its owner than to a jeweller, and the imprint of a child's hand on dried clay is priceless to a loving grandparent. Moreover, not only can gift-giving add value for the recipient, but it can be fun for the giver too. It is good, in other words, to give as well as to receive."