The canon of economics经济学经典

Economics focus
经济聚焦

The canon of economics
经济学经典

The best journal in the discipline picks its best papers
最佳学术期刊选出最佳论文

Feb 24th 2011 | from the print edition



ONE hundred years ago, in March 1911, the American Economic Review (AER) published its first article—on irrigation in the “sun-blistered” deserts of the western United States. The article described how the “fervid suns of May and June” melted “vast beds of snow and ice”, so that “springs and torrents rush down to the lowlands” and “the rivers overflow their banks”.
一百年前的1911年3月，《美国经济评论》（American Economic Review）登出了第一篇文章，内容是关于美国西部被太阳晒到起泡的沙漠的灌溉的。文章描绘了“五六月的骄阳”如何融化了“巨大的冰雪床”，以至于“泉水和溪流朝低地奔腾而下”，“河水漫过了堤岸”。

It is fair to say that the journal’s prose style has rushed downhill since those first lyrical pages. But if the AER’s opening article ranks among the best-written in the review’s history, it does not rank among the best. To mark its centenary issue, the journal asked six eminent economists to trawl through the thousands of papers that followed and pick the top 20. The results, with links to all 20 papers, are available online.*
平心而论，除了开头几页的抒情文字，《美国经济评论》的文风就乏善可陈了。但开山之文尽管文采斐然，可列《美国经济评论》百年翘楚，其质量却称不上出类拔萃。在标志其跨越百年的最新一期中，《美国经济评论》邀请了六位著名经济学家从数千篇文章中遴选出最好的20篇。遴选结果与所有20篇文章的链接已公布在网上。

The links are worth clicking on. Many of these papers are more cited than read. They are known not by their full titles, but by the author-and-date shorthand (Modigliani and Miller, 1958; Friedman, 1968; Diamond and Mirrlees, 1971) used in references. Reading them in the original yields some pleasing rediscoveries.
这些链接值得点击。其中许多篇被引用的次数甚至比阅读的次数还要多。它们的作者-日期简称（Modigliani and Miller, 1958; Friedman, 1968; Diamond and Mirrlees, 1971，用于参考文献中）比标题更出名。阅读原始文献能重新发现一些颇有兴味的东西。

Unsurprisingly, the list includes the 1955 paper by Simon Kuznets explaining why inequality might first rise then fall in the course of economic development. Surprisingly, nowhere in the paper did he actually draw the “Kuznets curve” that is now inseparable from his name. (He described the arc of inequality as a “long swing” instead.) Robert Mundell’s 1961 theory of “optimum currency areas”, which lays out the conditions for a workable currency union, is now often cited by the euro’s critics. Ironic, therefore, to note that Mr Mundell wrote the paper to show why flexible exchange rates were impractical because many nations are not optimal currency areas either. Should every local “pocket of unemployment” have a “separate currency”, he snorted.
西蒙•库兹涅茨1955年解释为何不平等程度会随着经济发展先上升后下降的论文也在20佳之列，这毫不令人意外。令人意外的是，已与作者密不可分的“库兹涅茨曲线”其实并没有出现在这篇论文中。（他将不平等程度曲线描述为“长波”。）罗伯特•蒙代尔1961年提出的“最优货币区”理论给出了货币联盟可能成立的情形，如今经常被欧元批评者引用。这显得有些滑稽，因为他的这篇论文本是论证在许多国家根本不是最优货币区的情况下，灵活的汇率是如何不切实际的。蒙代尔不屑的哼道，每个“失业率不同”的地方都应该有“单独的货币”。

With one or two exceptions, the chosen papers convey an impression of economics as a tidy, coherent discipline. The subjects covered are traditional: consumption, tax, currencies, inflation, that sort of thing. There are no excursions into sumo相扑 or intestinal worms. The furthest off-piste they go is Anne Krueger’s 1974 article on rent-seeking, explaining why people may lobby for governments to distort the economy.
除了一两个例外，入选的文章让人们感觉经济学是一门井然有序、讲究逻辑的学科。20佳论文的主题均是诸如消费、税收、货币、通胀之类的传统领域。没有一篇论文是关于相扑、蛔虫之类与经济学风马牛不相及的东西的。离题最远的一篇论文是安妮•克鲁格1974年关于寻租的文章。在这篇文章解释了为何人们会游说政府去干扭曲经济的事。

The papers are not bereft of whimsy, but it is confined to footnotes and asides. A 1972 paper by Armen Alchian and Harold Demsetz, for example, describes how the firm evolved as an organisational form to prevent shirking in team production. A footnote explains why sportsmen do not shirk enough, overinvesting in their skills. (Teams care about coming top, as much as they care about being good, so if teams collectively agreed to lower their standards, they could achieve the same league rankings with less effort.) The two economists also explain why professors get away with “turpitudinal peccadillos” like stealing office stationery.
入选论文中不乏奇思怪想，但只限于脚注和旁白。比如，阿曼•阿尔钦和哈罗德•登姆塞茨在1972年的一篇论文中描述了企业是如何作为一种防止团队生产中的偷懒现象的组织形式演化的。其中的一个脚注解释了为什么运动员不会偷懒，而是孜孜不倦地提升技艺。（对一支运动队来说，优秀程度并不比名次更重要，因此如果运动队集体决定降低标准的话，他们是可以以更少的付出获得相同的联赛名次的。）阿尔钦和登姆塞茨还解释了教授偷取办公文具之类的“卑劣小伎俩”为何可以逍遥法外。

This consensus on the proper subject of economics also extends to method. The chosen economists mostly go about their business in a consistent way, refining, extending or occasionally bending a shared framework of analysis. Some of them make their colleagues’ lives easier by suggesting convenient tricks and techniques to make a theory testable (such as the consumer-demand equations set out in 1980 by Angus Deaton and John Muellbauer), to make a notion easy to model (see the 1977 paper by Avinash Dixit and Joseph Stiglitz on differentiated products and increasing returns to scale) or both (the production function pioneered in 1928 by Charles Cobb and the inimitable Paul Douglas).
入选论文不仅主题集中于传统经济学领域，使用的方法也是如此。入选的经济学家绝大多数以一以贯之的方式做学问，在常规的分析框架下进行改进和扩展，偶尔也会另辟蹊径。其中一些人发展出了方便的技巧和方法，或是使理论变得可验证（比如安格斯•迪顿和约翰•米尔鲍尔1980年给出的消费者需求方程组），或是让概念更容易被建模（见阿维纳什•迪克西特和约瑟夫•斯蒂格利茨1977年关于差异产品和规模报酬递增的论文），或是两者皆是（查尔斯•柯布和无与伦比的保罗•道格拉斯1928年在生产函数上所做的先驱性工作），从而为同侪提供了极大的便利。

Several papers spot a real-world phenomenon that sits uneasily with the discipline’s ruling assumptions. Why do people in developing countries leave undermanned farms to languish in urban unemployment, for example? The papers then show that one or two tweaks to the assumptions can bring the problem to heel—in this instance, the artificially high wages paid by city jobs offset the smaller chance of landing one.
不少论文直指经济学基本假设难以处理的真实世界。比如，为何发展中国家的人民要离开人手不足的农村，到城市里去经受失业的折磨？有几篇论文显示，只要假设稍作改动，就能轻松解决问题。刚才这个问题答案是城市工作岗位的工资被人为限定在较高水平，补偿了在城市立足的高难度。

Thirty-somethings
三十余年来……

The most recent entry to the top 20 is Robert Shiller’s 1981 paper documenting the excessive volatility of stock prices. Nothing else in the past 30 years made the cut—even though submissions to the AER have swelled in that time and its acceptance rate has plunged. Douglas Bernheim, one of the six pop-pickers, says that each of them would probably have included “at least a couple of more recent papers” on their list. “But as we move from older to younger papers, assessments vary more from person to person.”
在20佳论文中，最为晚近的一篇是罗伯特•希勒1981年关于股价过度波动的论文。过去30年来，《美国经济评论》的投稿数量有了很大增长，退稿率也大大提高了，但却没有一篇论文能够入围20佳。六名遴选者之一的道格拉斯•伯恩海姆（Douglas Bernheim）说，也许他们六个人每人都“至少选了两三篇近期论文”，“但随着我们的目光从老论文转向新论文，我们彼此之间的判断出现了越来越大的差异。”

Why is this? Mr Bernheim points out that younger papers are less time-tested. Economists can only forecast their worth, and these forecasts are rarely convincing enough to supplant one of the proven classics on the list. According to this view, some recent papers will eventually earn broad admiration. It is simply a question of time.
这是为什么呢？伯恩海姆指出，新论文所经受的时间检验不够充分。经济学家们只能预测它们的价值，但光凭预测很难令人信服地取代榜单中已被证明了的经典论文。根据这一观点，一些新文章最终会赢得广泛赞誉。这只是时间问题。

But perhaps it is also a question of the times. Economics has fragmented in the past 15-20 years, both in subject and technique. No aspect of human behaviour is off-limits and a miscellany of methods are in vogue, adding laboratory experiments, randomised trials and computer simulations to the traditionalist’s blackboard and chalk. Many of the brightest stars in economics parade their scepticism, insisting on how little economists really know (or indeed how little real economics they know). The discipline is more exciting, ingenious and intrepid as a result. But it is also unruly and untidy. Some economists are still patiently adding to a cairn of knowledge. Many are throwing rocks.
但这很有可能也是时代问题。过去15~20年来，经济学从主题到方法都出现了越来越细的分化。经济学已经涉及到人类行为的方方面面，多种方法混用也在风靡一时，不再局限于传统的黑板+粉笔，实验室实验、随机试验和计算机模拟都被用到了经济学研究中。不少明星经济学家喜欢标榜怀疑精神，大谈经济学家事实上是如何无知（或者对真正的经济学实在是所知甚少）。结果，经济学变得比以前更令人振奋、更灵光闪现、更勇往直前，也变得凌乱无序、缺乏章法。有些经济学家仍在循规蹈矩稳步向前，不少人则是在信马由缰。

It is harder than ever to keep abreast of progress. After running four issues a year for the past 100 years, the AER will this year publish six. The journal has already produced four specialised offshoots. Economics is producing a torrent of research, coursing in all directions. The rivers have overflowed their banks.
如今，时刻保持在最前沿已经相当困难了。过去100年来，《美国经济评论》每年只出版四期，但今年将增加至六期。《美国经济评论》已经创造了四大专业分支。经济学正在创造无孔不入的研究洪流。河水已经漫过了堤岸。

* http://pubs.aeaweb.org/doi/pdfplus/10.1257/aer.101.1.1
from the print edition | Finance and Economics