诺贝尔经济学奖缘何颁给契约理论专家
Bengt Holmström and Oliver Hart, two academics who developed modern ways to think about writing contracts in areas as diverse as car insurance, bonuses for chief executives and the provision of public services, have won the 2016 Nobel Prize for economics.
本特•霍姆斯特姆(Bengt Holmström，图右)和奥利弗•哈特(Oliver Hart，图左)赢得了2016年诺贝尔经济学奖。他们发展了思考如何写合同的现代化方式，这些合同涉及多个领域，包括汽车保险、首席执行官的奖金，以及公共服务的提供。
Professor Hart, a Briton based at Harvard University, and Professor Holmström, a Finn who teaches at the Massachusetts Institute of Technology, share the $925,000 award from the Swedish Riksbank in memory of Alfred Nobel, for their contribution to contract theory in the 1970s and 1980s.
哈特教授是在哈佛大学(Harvard University)工作的英国人，霍姆斯特姆教授是在麻省理工学院(MIT)执教的芬兰人。他们两人将分享来自瑞典央行(Swedish Riksbank)的92.5万美元奖金，以表彰他们在20世纪70年代和80年代对契约理论作出的贡献。诺贝尔经济学奖是为了纪念阿尔弗雷德•诺贝尔(Alfred Nobel)而设立的。
Their work does not prescribe what a good contract is, since that depends on circumstances, but instead helps parties think clearly about important design issues.
他们的研究并没有说明一份好的合同应该是什么样的（因为这要视乎具体情况而定），而是帮助当事人想清楚重要的设计问题。
Some contracts are straightforward to write.
有些合同写起来直截了当。
But in instances where it is difficult to monitor whether people have stuck to their side of a deal or where it is difficult to specify all future eventualities, the work gives practical advice on how to achieve the best outcome for both sides and how to avoid common pitfalls in contract design.
但在很难监测人们是否履行他们的义务，或者很难列举所有未来可能事态的情况下，他们的研究给出了实用建议，阐明如何实现对双方都是最好的结果，以及如何避免常见的合同设计陷阱。
The theory has been relevant in understanding the design of performance bonuses, why gig economy companies can enforce rigid contracts and why the US justice department has decided to phase out the use of private contractors in the prison service.
契约理论有助于理解绩效奖金的设计，为什么零工经济企业可以采用硬性合同，以及美国司法部为什么决定逐步淘汰在监狱系统使用私营部门的承包商。
Many contract design elements were already widespread before being formalised in contract theory.
许多合同设计要素在被契约理论正式纳入之前就已广泛存在。
Car insurance contracts, for example, have for decades avoided providing full cover in the event of accidents, forcing drivers to pay a proportion of the costs from a crash.
例如，汽车保险合同几十年来一直避免完全覆盖事故，而是迫使驾车者为碰撞事故支付一定比例的代价。
Contract theory formalises the common sense that excess payments help prevent careless driving, which insurance companies cannot perfectly monitor.
契约理论正式确立了这种常识：自掏腰包的额外费用有助于阻止粗心驾驶，而后者是保险公司无法完美监测的。
Similarly, employers have long offered bonuses as well as fixed payments in an attempt to motivate better performance.
同样，雇主早就会提供固定报酬以外的奖金以激励更好的绩效。
But the contribution of Prof Holmström was to determine that an optimal contract should link payments to outcomes that reveal the performance of either party to a contract.
霍姆斯特姆教授的贡献是确定一份最优化的合同应该把报酬与结果（揭示任何一方履行合同的表现）联系起来。
Even today, many chief executives are rewarded for the strong performance of their company’s share price, despite wide acknowledgment that this can sometimes be the result of their luck in being in post at a time of rising financial markets.
即使在当今，许多首席执行官们也会因为公司股价表现强劲而获得奖励，尽管人们广泛承认，有时这可能只是由于他们的运气较好，在金融市场上涨期间执掌公司。
Prof Holmström’s work showed it was much better for shareholders to reward managers based on the relative performance of their company compared with others.
霍姆斯特罗姆教授的研究显示，对股东来说更好的做法是根据其公司相比业内同行的相对表现来奖励管理人员。
The more difficult it is to observe the effect of an individual’s actions, the less remuneration should be performance-based, according to Prof Holmström’s findings.
霍姆斯特姆教授的研究发现，越难观察一个人行动的效果，与绩效挂钩的薪酬比例就应该越低。
Where there is significant uncertainty, it is better to pay fixed salaries, modern contract theory now states.
现代契约理论认为，若存在显著不确定性，最好支付固定薪酬。
But for Uber drivers or couriers, the theory demonstrates why their pay can be based so heavily on performance.
但是，对于优步(Uber)司机或快递员，该理论展示了为什么他们的报酬可以如此大幅度取决于绩效。
With the technology underpinning the gig economy enabling employers in the sector to have almost complete information about their workers, those companies can perform more strongly by using heavily performance-based remuneration.
支撑零工经济的技术使雇主能够几乎完全掌握有关工人的信息，这些企业通过采用在很大程度上基于绩效的薪酬，就可以实现更为强劲的业绩。
However, while Uber drivers’ performance might be easy to monitor, this is trickier in occupations where output is more difficult to measure, where people work in teams and where certain incentives may lead to distorted outcomes.
然而，尽管优步司机的绩效也许容易监测，但在某些职业（产出更难衡量、人们在团队中工作、某些激励可能导致扭曲结果），要做到这一点就比较棘手。
Prof Hart’s contribution to contract theory since the mid 1980s has revolved around how best to write contracts that cover eventualities that cannot be precisely specified in advance.
哈特教授自20世纪80年代中期以来对契约理论作出的贡献，围绕着如何写合同最好，以覆盖不能预先精确列举的各种可能事态。
His insight was that where it was futile to try to specify what should happen, it was important to write down who had the right to decide when both parties to a contract could not agree.
他的高见是，在试图罗列未来情形徒劳无益的情况下，重要的是写明若合同双方意见不同，哪一方将有权做出决定。
This is most useful in financial contracts, such as providing finance to entrepreneurs.
这在财务契约中（比如为创业家提供资金）最为有用。
Rather than paying people as employees to innovate, Mr Hart found it was best to allow them to take control as entrepreneurs so they gained most of the profits of their efforts.
哈特教授发现，与其把人才当作雇员，支付工资让他们创新，不如让他们成为拥有控制权的创业家，获益于自己努力所取得的大部分利润。
The outcome is that entrepreneurs get to control their companies if performance is good but progressively lose control as it worsens.
结果是，如果绩效良好，创业家能控制自己的企业，而如果绩效恶化，他们将逐渐失去控制。
Some contracts are particularly difficult to specify, such as in the provision of public services.
有些合同特别难写，比如提供公共服务的合同。
Public providers run by a manager on a fixed salary often have little incentive to improve efficiency or service quality, while private providers often make efforts to cut costs at the expense of quality.
公共部门提供商由一名拿固定工资的管理人执掌，往往毫无提高效率或服务质量的动力，而私营部门提供商往往以牺牲质量为代价削减成本。
For many years the latter was thought to be a better solution than the former, but Prof Hart’s work highlighted difficulties with contracts relating to prison services.
多年来，私营部门提供商被认为是比公共部门提供商更好的解决方案，但哈特教授的研究突显了监狱服务合同的困难。
His work was instrumental in the US decision to shift prison provision back into the public sector after his findings on such incomplete contracts demonstrated the efficiency incentive was too strong and that jail conditions had as a result deteriorated unacceptably.
他对此类不完全合同的研究发现，效率激励太强大了，其结果是监狱条件出现了不可接受的恶化。这些发现对美国政府决定把监狱服务转回公共部门起到了重要作用。
