諾貝爾經濟學獎緣何頒給契約理論專家
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，圖右)和奧利弗•哈特(Oliver Hart，圖左)贏得了2016年諾貝爾經濟學獎。他們發展了思考如何寫合同的現代化方式，這些合同涉及多個領域，包括汽車保險、首席執行官的獎金，以及公共服務的提供。
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學(Harvard University)工作的英國人，霍姆斯特姆教授是在麻省理工學院(MIT)執教的芬蘭人。他們兩人將分享來自瑞典央行(Swedish Riksbank)的92.5萬美元獎金，以表彰他們在20世紀70年代和80年代對契約理論作出的貢獻。諾貝爾經濟學獎是爲了紀念阿爾弗雷德•諾貝爾(Alfred Nobel)而設立的。
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.
他們的研究並沒有說明一份好的合同應該是什麼樣的（因爲這要視乎具體情況而定），而是幫助當事人想清楚重要的設計問題。
Some contracts are straightforward to write.
有些合同寫起來直截了當。
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.
但在很難監測人們是否履行他們的義務，或者很難列舉所有未來可能事態的情況下，他們的研究給出了實用建議，闡明如何實現對雙方都是最好的結果，以及如何避免常見的合同設計陷阱。
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.
契約理論有助於理解績效獎金的設計，爲什麼零工經濟企業可以採用硬性合同，以及美國司法部爲什麼決定逐步淘汰在監獄系統使用私營部門的承包商。
Many contract design elements were already widespread before being formalised in contract theory.
許多合同設計要素在被契約理論正式納入之前就已廣泛存在。
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，汽車保險合同幾十年來一直避免完全覆蓋事故，而是迫使駕車者爲碰撞事故支付一定比例的代價。
Contract theory formalises the common sense that excess payments help prevent careless driving, which insurance companies cannot perfectly monitor.
契約理論正式確立了這種常識：自掏腰包的額外費用有助於阻止粗心駕駛，而後者是保險公司無法完美監測的。
Similarly, employers have long offered bonuses as well as fixed payments in an attempt to motivate better performance.
同樣，僱主早就會提供固定報酬以外的獎金以激勵更好的績效。
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.
霍姆斯特姆教授的貢獻是確定一份最優化的合同應該把報酬與結果（揭示任何一方履行合同的表現）聯繫起來。
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.
即使在當今，許多首席執行官們也會因爲公司股價表現強勁而獲得獎勵，儘管人們廣泛承認，有時這可能只是由於他們的運氣較好，在金融市場上漲期間執掌公司。
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.
霍姆斯特羅姆教授的研究顯示，對股東來說更好的做法是根據其公司相比業內同行的相對錶現來獎勵管理人員。
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發現，越難觀察一個人行動的效果，與績效掛鉤的薪酬比例就應該越低。
Where there is significant uncertainty, it is better to pay fixed salaries, modern contract theory now states.
現代契約理論認爲，若存在顯著不確定性，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，對於優步(Uber)司機或快遞員，該理論展示了爲什麼他們的報酬可以如此大幅度取決於績效。
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.
支撐零工經濟的技術使僱主能夠幾乎完全掌握有關工人的信息，這些企業通過採用在很大程度上基於績效的薪酬，就可以實現更爲強勁的業績。
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，儘管優步司機的績效也許容易監測，但在某些職業（產出更難衡量、人們在團隊中工作、某些激勵可能導致扭曲結果），要做到這一點就比較棘手。
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世紀80年代中期以來對契約理論作出的貢獻，圍繞着如何寫合同最好，以覆蓋不能預先精確列舉的各種可能事態。
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.
他的高見是，在試圖羅列未來情形徒勞無益的情況下，重要的是寫明若合同雙方意見不同，哪一方將有權做出決定。
This is most useful in financial contracts, such as providing finance to entrepreneurs.
這在財務契約中（比如爲創業家提供資金）最爲有用。
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.
哈特教授發現，與其把人才當作僱員，支付工資讓他們創新，不如讓他們成爲擁有控制權的創業家，獲益於自己努力所取得的大部分利潤。
The outcome is that entrepreneurs get to control their companies if performance is good but progressively lose control as it worsens.
結果是，如果績效良好，創業家能控制自己的企業，而如果績效惡化，他們將逐漸失去控制。
Some contracts are particularly difficult to specify, such as in the provision of public services.
有些合同特別難寫，比如提供公共服務的合同。
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.
公共部門提供商由一名拿固定工資的管理人執掌，往往毫無提高效率或服務質量的動力，而私營部門提供商往往以犧牲質量爲代價削減成本。
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.
多年來，私營部門提供商被認爲是比公共部門提供商更好的解決方案，但哈特教授的研究突顯了監獄服務合同的困難。
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.
他對此類不完全合同的研究發現，效率激勵太強大了，其結果是監獄條件出現了不可接受的惡化。這些發現對美國政府決定把監獄服務轉回公共部門起到了重要作用。
