经济学人下载:信息不对称之柠檬市场理论与效应(下)

Signalling explains all kinds of behaviour.
信号行为能够解释各种各样的行为。

Firms pay dividends to their shareholders, who must pay income tax on the payouts.
企业给股东支付红利，股东必须为这笔支出缴纳收入税。

Surely it would be better if they retained their earnings, boosting their share prices, and thus delivering their shareholders lightly taxed capital gains.
如果留下盈利，刺激股价上涨，从而分发给股东课税较轻的资本利得会更好。

Signalling solves the mystery: paying a dividend is a sign of strength, showing that a firm feels no need to hoard cash.
信号行为能够解开这个迷团：支付红利是一种力量的信号，表明企业认为无需囤积现金。

By the same token, why might a restaurant deliberately locate in an area with high rents?
同理，为什么餐馆要有意选址于高房租地区呢？

It signals to potential customers that it believes its good food will bring it success.
这是在向潜在的客户发出相信自己的美食会带给它成功的信号。

Signalling is not the only way to overcome the lemons problem.
信号行为不是克服柠檬问题的唯一办法。

In a 1976 paper Mr Stiglitz and Michael Rothschild, another economist, showed how insurers might “screen” their customers.
在1976年的一篇论文中，斯蒂格利茨与另一名经济学家迈克尔·罗斯柴尔德展示了保险商可能如何 “筛选” 客户的问题。

The essence of screening is to offer deals which would only ever attract one type of punter.
筛选行为的关键是提供永远只吸引某类客户的协议。

Suppose a car insurer faces two different types of customer, high-risk and low-risk.
假设，汽车保险商面对两种不同类型的客户，一类是高风险的，一类是低风险的。

They cannot tell these groups apart; only the customer knows whether he is a safe driver.
他们无法将其区分开来；只有客户才知道自己是否是安全的驾驶员。

Messrs Rothschild and Stiglitz showed that, in a competitive market, insurers cannot profitably offer the same deal to both groups.
罗斯柴尔德先生和斯蒂格利茨先生指出，在竞争市场中，保险商无法有盈利地把同样的保单同时提供给这两类人。

If they did, the premiums of safe drivers would subsidise payouts to reckless ones.
倘若如此，安全的驾驶员的保费就会补贴对鲁莽的驾驶员的赔付。

A rival could offer a deal with slightly lower premiums, and slightly less coverage, which would peel away only safe drivers because risky ones prefer to stay fully insured.
对手可能会提供一份保费稍微低一点、承保范围稍微小一点的保单，由于风险大的驾驶员倾向于保持全保，这份保单只会剔出安全的驾驶员。

The firm, left only with bad risks, would make a loss.
鉴于剩下来都是高风险的业务，保险企业会出现损失。

(Some worried a related problem would afflict Obamacare, which forbids American health insurers from discriminating against customers who are already unwell: if the resulting high premiums were to deter healthy, young customers from signing up, firms might have to raise premiums further, driving more healthy customers away in a so-called “death spiral”. )
(有人担心，一个相关的问题会困扰禁止美国医疗保险商歧视性对待已经患病的客户的奥巴马医改：如果由此产生的高额保费把健康的、年轻的客户吓得不签约的话，保险企业可能不得不进一步提高保费，迫使更多的健康客户脱离所谓的 “死亡漩涡”。)

The car insurer must offer two deals, making sure that each attracts only the customers it is designed for.
汽车保险商必须提供两份保单，确保每份保单只吸引为之所设计的客户。

The trick is to offer one pricey full-insurance deal, and an alternative cheap option with a sizeable deductible.
窍门是提供一分昂贵的全保保单和一份便宜的自费比例大的替代保单。

Risky drivers will balk at the deductible, knowing that there is a good chance they will end up paying it when they claim.
由于知道自己在理赔时终将为自费条款掏腰包的概率很大，风险大的驾驶员会避开自费条款多的保单。

They will fork out for expensive coverage instead.
相反，他们会为昂贵的承包范围出钱。

Safe drivers will tolerate the high deductible and pay a lower price for what coverage they do get.
安全驾驶员会容忍高额自费条款，并为他们得到的承包范围支付较低的价格。

This is not a particularly happy resolution of the problem.
这不是这一问题的特别愉快的解决之道。

Good drivers are stuck with high deductibles—just as in Spence's model of education, highly productive workers must fork out for an education in order to prove their worth.
好驾驶员受高额自费条款所困扰——如同在斯彭斯的教育模型中，高生产率的工人必须要为了证明他们的价值而为学历花很多钱一样。

Yet screening is in play almost every time a firm offers its customers a menu of options.
然而，在几乎每一次企业为客户提供一份选项菜单时，筛选行为都在发挥作用。

Airlines, for instance, want to milk rich customers with higher prices, without driving away poorer ones.
例如，航空公司想用较高的价格培养富有的客户，同时又不赶走较穷的客户。

If they knew the depth of each customer's pockets in advance, they could offer only first-class tickets to the wealthy, and better-value tickets to everyone else.
如果事先知道每一位客户的钱包的深浅，他们可能只给富人提供头等舱机票，给其他人提供性价比更高的机票。

But because they must offer everyone the same options, they must nudge those who can afford it towards the pricier ticket.
但是，由于他们必须给每一个人都提供同样的选项，因而必须把能够出得起钱的人推向价格更高的机票。

That means deliberately making the standard cabin uncomfortable, to ensure that the only people who slum it are those with slimmer wallets.
这意味着有意让标准仓不舒适，确保唯一屈尊标准仓的是钱包较瘪之人。

Adverse selection has a cousin.
逆向选择有一位近亲。

Insurers have long known that people who buy insurance are more likely to take risks.
保险商早就知道，投保的人更有可能去冒险。

Someone with home insurance will check their smoke alarms less often; health insurance encourages unhealthy eating and drinking.
买了房屋保险的人会降低检查烟雾警报装置的频率；健康险会促进不健康的饮食行为。

Economists first cottoned on to this phenomenon of “moral hazard” when Kenneth Arrow wrote about it in 1963.
经济学家最初开始理解这种 “道德风险” 现象是肯尼斯·阿罗在1963年论述它的时候。

Moral hazard occurs when incentives go haywire.
道德风险发生在激励失控之时。

The old economics, noted Mr Stiglitz in his Nobel-prize lecture, paid considerable lip-service to incentives, but had remarkably little to say about them.
斯蒂格利茨在他的诺奖演说中指出，老的经济学曾给激励开出了大量的空头许诺，但极少说起它们。

In a completely transparent world, you need not worry about incentivising someone, because you can use a contract to specify their behaviour precisely.
在一个完全透明的世界中，由于可以用合约精确地规范他人行为，人们根本无需为激励他人而操心。

It is when information is asymmetric and you cannot observe what they are doing (is your tradesman using cheap parts? Is your employee slacking? ) that you must worry about ensuring that interests are aligned.
只有在信息不对称或者看不到别人正在做什么 (店员是否正是使用廉价部件？雇员是否正在偷懒？)的情况下，才必须为确保利益均衡而操心。

Such scenarios pose what are known as “principal-agent” problems.
这类情况所引发的就是众所周知的 “委托—代理” 问题。

How can a principal (like a manager) get an agent (like an employee) to behave how he wants, when he cannot monitor them all the time?
(类似于管理者的) 委托人怎么才能让 (类似于雇员的) 代理人在自己无法时刻监控他们的时候，按照他的意愿去做事呢？

The simplest way to make sure that an employee works hard is to give him some or all of the profit.
最简单的办法是确保努力工作的雇员把盈利部分或者全部地交给他。

Hairdressers, for instance, will often rent a spot in a salon and keep their takings for themselves.
例如，理发师经常会在沙龙内租用一处地点，把收入放进自己的腰包。

But hard work does not always guarantee success: a star analyst at a consulting firm, for example, might do stellar work pitching for a project that nonetheless goes to a rival.
但是，努力工作并非总能保证成功：例如，咨询公司的明星分析师可能会为了拿到一个落入对手手中的项目拼命工作。

So, another option is to pay “efficiency wages”.
因而，另一个选项是支付 “效率工资”。

Mr Stiglitz and Carl Shapiro, another economist, showed that firms might pay premium wages to make employees value their jobs more highly.
斯蒂格利茨和另一位经济学家卡尔·夏皮罗指出，企业或许会为了让雇员更重视他们的工作而支付奖励工资。

This, in turn, would make them less likely to shirk their responsibilities, because they would lose more if they were caught and got fired.
反过来，这会让雇员不太可能去推卸责任，因为如果被抓或是遭到解雇，他们会失去更多。

That insight helps to explain a fundamental puzzle in economics: when workers are unemployed but want jobs, why don't wages fall until someone is willing to hire them?
这个真知灼见有助于解释经济学的一个根本之谜：当工人失业但是想要工作时，为什么工资直到有人原意雇佣才下降呢？

An answer is that above-market wages act as a carrot, the resulting unemployment, a stick.
答案是：高于市场的工资扮演的是胡萝卜的角色，由此而造成的失业则是大棒。

And this reveals an even deeper point.
而且这还揭示出更深的一点。

Before Mr Akerlof and the other pioneers of information economics came along, the discipline assumed that in competitive markets, prices reflect marginal costs: charge above cost, and a competitor will undercut you.
在阿克洛夫和信息经济学的其他先驱出现之前，这门学科假设，在竞争市场中，价格反映边际成本：只要收费高于成本，竞争对手就会以低于你的价格出售。

But in a world of information asymmetry, “good behaviour is driven by earning a surplus over what one could get elsewhere,” according to Mr Stiglitz.
但是，据斯蒂格利茨，在信息不对称的世界中，“良好的行为是由赚取高于他处所得的盈余所推动的”。

The wage must be higher than what a worker can get in another job, for them to want to avoid the sack; and firms must find it painful to lose customers when their product is shoddy, if they are to invest in quality.
工资必须要高于工人在另一个工作中的所得；企业必须在产品粗制滥造时发现失去客户是痛苦的。

In markets with imperfect information, price cannot equal marginal cost.
在信息是不完全的市场中，价格不可能等于边际成本。

The concept of information asymmetry, then, truly changed the discipline.
如此说来，信息不对称的概念真正改变了这门学科。

Nearly 50 years after the lemons paper was rejected three times, its insights remain of crucial relevance to economists, and to economic policy.
在柠檬论文遭到三次拒绝将近50年后，它的真知灼见仍与经济学家和经济政策密切相关。

Just ask any young, black Washingtonian with a good credit score who wants to find a job.
只要问问华盛顿州的任何一位信用得分良好的年轻人或者黑人即可。