[单项选择]The psychology of warranties保单心理学 Protection racket保护之诈 If extended guarantees are overpriced, why are they so popular Customers tend to agonise over the relative merits of different models of electronic goods such as digital cameras or plasma televisions. But when they get to the till, many spend freely on something they barely think about at all: an extended warranty, which is often more profitable to the retailer than the device it covers. Shoppers typically pay 10-50% of the cost of a product to insure it beyond the term covered by the manufacturer’s guarantee. 71. Yet products rarely break within the period covered, and repairs tend to cost no more than the warranty itself. 72. So why, asks a paper published in the December issue of the Journal of Consumer Research, do so many consumers still buy extended warranties The authors—Tao Chen of the University of Maryland, Ajay Kalra of Rice University