【英语生活】朋友分账为何自私？

In your books and columns you have claimed that when people split the bill equally in restaurants they tend to take advantage of each other by ordering expensive dishes. I wonder if this is really true. Wouldn't friends be more considerate of each other?
Considerate restaurant-goer, London

Dear CRG,

The “diner's dilemma” you describe is a kind of prisoner's dilemma, and in theory people should behave exactly as I have described. But many laboratory experiments suggest we are not as selfish as economists' models claim. So you are right to ask for more evidence.

The economists Uri Gneezy, Ernan Haruvy and Hadas Yafe have been looking into this. They seated various groups of six diners at a nice restaurant in Haifa, Israel, and noted how they responded to different payment schemes. Some ate for free, and they ordered a lot. Others paid for their own order, and they ordered sparingly. Between those two extremes were those who split the bill with the other five diners: they took advantage of their fellow diners, as I would have expected.

Perhaps they were somewhat inhibited by the embarrassment of free-riding, though? It seems not. When the experimenters, in a further trial, told diners that they would pay one-sixth of their individual bill only, they faced the same costs of over-ordering as in the “split the bill” case, but if they made extravagant choices their dining companions did not suffer. Yet they ordered much the same as in the “split the bill” case, suggesting that saving money for fellow diners was not much of a consideration.

It's worth emphasising that this experiment seated strangers together, not friends. Perhaps people are more generous when it comes to friends. Or perhaps they are simply more careful about their reputations.

您在著作和专栏里声称，当人们平摊餐馆用餐费用时，往往会占别人的便宜，点昂贵的菜。我对这种说法的正确性表示怀疑。朋友们难道不会更加互相体谅吗？

体贴的餐馆用餐者，伦敦

亲爱的餐馆用餐者：

你描述的“用餐者困境”是一种囚徒困境，从理论上讲，人们的行为应该与我所描述的完全一致。但许多实验室实验显示，我们并不像经济学家的模型所宣称的那样自私。因此，你要求更多证据的想法是正确的。

经济学家尤里•格尼茨(Uri Gneezy)、埃尔纳•哈鲁维(Ernan Haruvy)和哈达什• 雅菲(Hadas Yafe)一直在研究这个问题。他们在以色列海法一家高档餐馆，将受调查者分成不同的小组，每组6人，观察他们对不同的付费方案的反应。有一些小组是免费用餐，于是他们点了一大堆。还有一些小组是个人支付自己的账单，他们点餐时就很节省。处于两个极端之间的是那些与其他五位共餐者平摊费用的人：正如我所预期的那样，他们会占共餐者的便宜。

或许，他们会因为坐享其成感到尴尬而有所收敛？似乎并非如此。在另一个实验中，经济学家告诉用餐者，他们仅需支付自己那份账单的六分之一，这时过度点餐带给他们的成本与“平分账单”实验中一样，但如果他们铺张浪费，其他共餐者也不会有损失。但他们仍点了与“平分账单”实验中几乎一样的菜，这说明，他们并没怎么考虑为同伴省钱。

值得强调的一点是，上述实验的共餐者都是陌生人，并非朋友。或许人们对待朋友会更慷慨一些。又或许，他们不过是更在乎自己的名誉。

译者/陈云飞