Free exchange: Reasonable doubt 自由交流：合理的怀疑

　　Richard Thaler wins the Nobel prize for economic sciences 理查德·赛勒赢得诺贝尔经济学奖

　　The credit-card bill arrives. 信用卡账单到了。

　　You have enough money in a savings account to pay it off—the sensible thing to do, arithmetically speaking,  你在储蓄账户中有足够的钱把账单付清——从算术上来说，这是该做的合理之事，

　　since the interest rate on the credit-card balance far exceeds that earned on the savings. 因为信用卡余额的利率远远超出储蓄所得。

　　Yet you leave the savings untouched, and pay only as much of the bill as your current-account balance allows. 然而，你却让储蓄不被触及，仅支付你的常规账户余额允许你支付的那部分账单。

　　What looks a daft choice to most economists makes perfect sense to Richard Thaler, who on October 9th was awarded the Nobel prize for economics for his work in behavioural economics. 对大多数经济学家看起来来是愚蠢的选择，对10月9日因其对行为经济学的研究而荣获诺贝尔经济学奖的理查德·赛勒来说却具有重大的意义。

　　Mr Thaler helped demonstrate how human reasoning diverges from that of the perfectly rational homo economicus used in most economic modelling. 赛勒促成了人类推理行为如何迥异于被用在大多数经济学建模行为中的完全理性的经理人推理行为的阐释。

　　The world, and the field of economics, is better for his contributions. 这个世界以及经济学，因为他的贡献而愈发美好。

　　Economists mostly recognise that normal people fall short of perfect rationality in day-to-day decision-making. 经济学家大都承认，普通人在日常决策行为中缺乏完全理性。

　　Economic modelling requires simplification, however,  然而，经济学上的建模行为要求简单化，

　　and economists generally suppose that theories assuming people are well-informed and rational offer the best available account of economic activity. 同时经济学家通常认为，假设人们已经被很好地告知的理论以及理性，给经济行为提供了最好的可用账户。

　　Over time, however, scholars have built up an imposing list of the ways in which humans systematically refuse to behave as the models predict. 然而，长期以来，学界却形成了一份堂堂正正的有关人类用以系统性地拒绝如模型所预期地那样行为的方法的名单。

　　Economists such as Herb Simon (who won the Nobel in 1978) , Daniel Kahneman (2002) and Robert Shiller (2013) are celebrated for their contributions to this effort. （1978年赢得诺贝尔奖的）赫伯·西蒙、（2002年获奖的）丹尼尔·卡尼曼和（2013年获奖的）罗伯特·席勒等经济学家，已经因为他们对这方面尝试的贡献而为人称道。

　　But perhaps more than any other scholar, Mr Thaler lifted behavioural economics to prominence, and helped put its lessons into practice. 但是，赛勒可能比任何其他学者都要多地，将行为经济学提升到了突出地位，让这门科学的研究成果走入了实践。