本人在经济和管理学受过若干训练，就此领域的现状也常有不满，并时常提出批评。不过对于过激的贬斥，却认为有必要说句公道话，指陈一二。

经济学纵有诸般不是，饱受批评，然而比起政客和大众，还是要略高一头。其前提当然是，经济学人头脑足够冷静，还没受着太多的利益的强力忽悠。

这里我愿借用一篇精短的演讲来说明这一观点。演讲者萨金特是著名的美国经济学家，2012年的诺奖得主，2007年在伯克莱加州大学经济学院的毕业典礼上的讲话。通篇演辞不超过五分钟，几百个词，对经济分析和经济学人的职责所做的概述，却是无比简约。我还以为萨金特说得相当精准，读了我的汉译，相信你或许也会同意。

萨金特开宗明义说，经济学不过是组织提炼过的常情常理而已。接着他谈了经济学科的教学取得的若干有价值的结论：

1. 许多事情虽然可欲，然而却不可操作；

2. 个人的追求和群体的利益往往必得有所取舍（trade-offs）；

3. 与自己相比，总有人在能力、努力和偏好上了解更为深入；

4. 任何人，包括你希望扶持的对象，总会响应激励，逐利而动的。这是为什么社会保障等系统的运作，结果老是与设计的初衷大为走样；

5. 平等和效率并不一致，而往往是此消彼长的关系；

6. 当一个经济体或一种博弈处于均衡状态时，人们满足于他们已做的选择。这是为什么善意的局外人要谋求改变，不管促进或是促退的变化，都很困难；

7. 你迟早会对激励产生响应。有些承诺你纵然想履行却做不到，原因就在于此。他人也不会相信你能履行承诺，要是这些承诺同你自己的利益不相符合的话。其中的教训是，在做出承诺前你得想明白啰，要是所处的情况发生了变化，你是否还愿意信守然诺。你的声誉与此可是大有关系的；

8.  政府机构和选民同样响应激励。这是政府机构往往会违约和爽约的原委；

9.  一代人总能设法把自己的亏空转移给下一代。这就是政府的国债和美国的社会保障系统正在干的事情。（新加坡的社会保障系统或许还干不了这个）；

10.  政府花了的钱，国民今天也好将来也罢，到头来总得偿还，或者通过明里纳的税，或者是通过暗中的通货膨胀；

11.  绝大多数的人都希望有其他的人来代他们偿付公共服务和政府转移支付（尤其是再分配给自己的好处）；

12.  正因为市场价格汇总了交易各方的信息，所以要预测股价、利率和汇率等等，是异常困难的。

Sargent’s Speech at Berkeley 2007

I remember how happy I felt when I graduated from Berkeley many years ago. But I thought the graduation speeches were long. I will economize on words.
Economics is organized common sense. Here is a short list of valuable lessons that our beautiful subject teaches.

1. Many things that are desirable are not feasible.
2. Individuals and communities face trade-offs.
3. Other people have more information about their abilities, their efforts, and their preferences than you do.
4. Everyone responds to incentives, including people you want to help. That is why social safety nets don’t always end up working as intended.
5. There are tradeoffs between equality and efficiency.
6. In an equilibrium of a game or an economy, people are satisfied with their choices. That is why it is difficult for well-meaning outsiders to change things for better or worse.
7. In the future, you too will respond to incentives. That is why there are some promises that you’d like to make but can’t. No one will believe those promises because they know that later it will not be in your interest to deliver. The lesson here is this：before you make a promise, think about whether you will want to keep it if and when your circumstances change. This is how you earn a reputation.
8. Governments and voters respond to incentives too. That is why governments sometimes default on loans and other promises that they have made.
9. It is feasible for one generation to shift costs to subsequent ones. That is what national government debts and the U.S. social security system do（but not the social security system of Singapore）.
10. When a government spends, its citizens eventually pay, either today or tomorrow, either through explicit taxes or implicit ones like inflation.
11. Most people want other people to pay for public goods and government transfers（especially transfers to themselves）.
12. Because market prices aggregate traders’ information, it is difficult to forecast stock prices and interest rates and exchange rates.

University of California at Berkeley graduation speech（2007）.