Bring a calculator with you

带上计算器去购物

WHEN retailers want to entice customers to buy a particular product, they typically offer it at a discount. According to a new study to be published in the Journal of Marketing, they are missing a trick.

零售商若想怂恿顾客购买某种产品，往往会打个折。一项即将发表在《市场营消杂志》（the Journal of Marketing）上的新研究表明，零售商们忽略了一个窍门。

A team of researchers, led by Akshay Rao of the University of Minnesota’s Carlson School of Management, looked at consumers’ attitudes to discounting. Shoppers, they found, much prefer getting something extra free to getting something cheaper. The main reason is that most people are useless at fractions.

由明尼苏达州大学卡尔森管理学院（University of Minnesota’s Carlson School of Management）的阿克什?劳（Akshay Rao）带领的一个研究团队就消费者对打折的态度进行了研究。他们发现，与较低的价格相比，购物者更喜欢获取免费赠品。主要是因为一涉及分数计算，多数人的脑子都转不过来。

Consumers often struggle to realise, for example, that a 50% increase in quantity is the same as a 33% discount in price. They overwhelmingly assume the former is better value. In an experiment, the researchers sold 73% more hand lotion when it was offered in a bonus pack than when it carried an equivalent discount (even after all other effects, such as a desire to stockpile, were controlled for).

例如，消费者往往很难意识到加量50%与打六七折其实是等价的。他们大多认为前者更划算。在一项实验中，研究人员以优惠装出售护手霜比打同等折扣多卖了73%（即使在其他影响，如顾客想多买一点，都被排除在外时也是如此）。

This numerical blind spot remains even when the deal clearly favours the discounted product. In another experiment, this time on his undergraduates, Mr Rao offered two deals on loose coffee beans: 33% extra free or 33% off the price. The discount is by far the better proposition, but the supposedly clever students viewed them as equivalent.

即使很明显是打折比较划算，消费者的数学盲点依然存在。在另一项实验中，这次实验对象是阿克什?劳的本科生，阿克什?劳给出了两种购买散装咖啡豆的方法：免费多送33%和价格降低33%。这个折扣比免费赠送划算得多，但那些看起来很聪明的学生却认为两者一样。

Studies have shown other ways in which retailers can exploit consumers’ innumeracy. One is to befuddle them with double discounting. People are more likely to see a bargain in a product that has been reduced by 20%, and then by an additional 25%, than one which has been subject to an equivalent, one-off, 40% reduction.

这些研究表明零售商还有其他方式可以利用消费者的数学盲点。其中一种就是用折上折来迷惑他们。人们往往会觉得，先打八折再打七五折比一次性只打六折更划算，其实两者根本一样。

Marketing types can draw lessons beyond just pricing, says Mr Rao. When advertising a new car’s efficiency, for example, it is more convincing to talk about the number of extra miles per gallon it does, rather than the equivalent percentage fall in fuel consumption.

阿克什?劳说，除了产品定价，人们还可以从这些研究中学到关于市场营销的其他技巧。例如，为一款新车的性能做广告，宣传每加仑的油能多跑多少英里比实质上能省多少油更有说服力。

There may be lessons for regulators too. Even well-educated shoppers are easily foxed. Sending everyone back to school for maths refresher-courses seems out of the question. But more prominently displayed unit prices in shops and advertisements would be a great help.

监管部门也可能从中学到东西。即使是受过良好教育的购物者也很容易被忽悠。让大家重返校园进修数学似乎不大可能，不过在商店和广告中更明显地标出产品单价将会有莫大的帮助。