Too much Maths and Too little History
我方观点是：现在经济学数学太多，历史太少
Ladies, Gentlemen, it's my job to try and persuade you, together with my colleague, Dr. Ha-Joon Chang (张夏准), of the truth of this proposition that there is too much maths and too little history in economics as it's currently taught, and conceived.（有效信息在后半句话）
To prove the proposition to you that is true. 让大家相信以下这个命题成立：那就是数学太多，历史太少。具体来说，是在教学和思考两个方面。
及物动词+宾语
And well, let's start off with an obvious question. Why do people study economics? Basically, to understand how economies（经济体） work（运行的方式）. And there are two different ways（角度/途径/手段） of understanding that: there's maths and there’s history, and they stand at opposite poles in terms of epistemology. 两种完全不同的认识事物的办法/处在认识论的两个极端
Let's take maths first. First, two things that maths tries to do, or claims to do. First of all, it's concerned with propositions (命题) that are necessarily true必然为真. That is, it's a branch of logic (逻辑学)属于逻辑学的范畴. But secondly, maths is concerned with propositions that can be proved可被验证的命题. And economists really endorsed maths in the second sense实际上是第二类, that is for generating provable propositions被用来产生可证实的命题.
Economy
But because the social system to which they apply maths is so complex, too complex to obtain reliable proofs, they're tempted by（倾向/偏向/被吸引） the first, or what I would call the platonic view of the subject(接近于第一种数学). And throughout the history of economics, one can find economists praising maths as the pathway to rigorous and elegant laws, akin, as one famous economist said, to the laws of celestial mechanics. 2
And this powerful temptation（强大的倾向性） - platonic temptation - was very well summarized by Nobel Prize winner Paul Krugman (保罗·克鲁格曼), when he wrote this, after the crash of 2008-2009: “The economics profession went astray（已经脱轨了）. Because economists as a group mistook （发部分经济学家都犯错了）// （mistake beauty for truth 误把华丽包装下的数学当做了真理）beauty, clad in impressive sounding mathematics, for truth. Economists fell in love with the old, idealized vision of an economy in which rational individuals interact in perfect markets, this time gussied up（爱上的是）（被花里胡哨的包装） with fancy mathematics.” 所谓经济就是理性的个体在完美的市场上互动。
It's an old vision, gussied up with fancy maths, and this insidious drift (在暗中传播)towards platonism explains something which a number of people have noticed, and that is the strong normative thrust （要点，要旨，principle of concern） of mathematical economics (数理经济学). 3 数理经济学主要关注怎样得出规律或者法则
Now（如果真的要翻译，就是“其实”）, an economic model is not like a model of an aeroplane（经济模型和航模不同） that is reality in a miniaturized form（并不是现实的缩小版）, it approaches reality by way of assumptions（based on assumptions）; and assumption is said to be chosen for its purchase on reality（能够较为客观地反映现实）. But in fact, more usually, assumptions are selected because of their convenience(假设之所以被选中是因为它们便于使用), typically, to make possible the solution of an equation by excluding extraneous（irrelevant 无关的因素） elements. But these acts of exclusion are choices which define the problem of interest, or direct the inquiry along certain paths that reflect the values of the economist（反映出经济学家的..）. （As）Soon as you get into an assumption-based mathematical modeling, you are actually inserting（自行加入） the problems you think are important. And also inserting（强加/自行引入） your view on how they ought to be discussed, and excluding other views on how they ought to be discussed. 4
And this exclusionism, （xxxism结尾不一定翻译为“主义”，可以是“行为“：排他行为）together with a virtual impossibility of proving anything, gives mathematical economics a powerful incentive（强烈的动机/充分的理由/高度倾向于/不可避免地促使） to make the real world more like their models than to make the models more like（更贴合） the real world（几乎证实不了任何事情）.
So there's one very, very important bias in mathematical economics.
What then is the role（充当什么样的角色） of history in economics? I would argue that the role of history is that of a reality check（现实检查/事实核查/）. Propositions from financial theory, such as risks are correctly priced on average, could not survive（这样的不适用/不符合金融市场的实际运作情况） any actual knowledge of financial market - the way financial markets work - or of economic history. 5 风险定价呢，用平均值来算就对了。用平均值来算风险定价是正确的
The branches of history especially suited for reality checks, are economic history, the history of economic thought, and political and social history. All are excluded or minimized 少之又少的内容 in the standard economics curriculum. They have been largely pushed out by mathematical economics. 很大程度上被数理经济学排挤了
The general reason for the exclusion of history is quite insidious （有一些阴暗的/不太明显，动机不太端正的）. It arises from the belief that everything to be learned from history has already been incorporated into the latest textbooks. And this ludicrous belief has taken a heavy toll on the study of economics thought. It arises, I think, from what I call physics envy [laughter]（是因为经济学家妒忌物理学/羡慕物理学）, some affliction to which many economists are prone. 6
Economics wants to be a hard science. If economics is like a natural science, the lessons of history have already been incorporated in the latest models, and no useful purpose is thereby served by recalling the history of mistakes. To quote, J. B. Say (萨伊), famous for something known as Say's Law (萨伊定律). And this was already true in the early 19th century, he wrote, “What useful purpose can be served by the study of absurd opinions and doctrines that have long since been exploded and deserve to be? It is mere useless pedantry to attempt to revive them, the more perfect the science becomes, the shorter becomes its history. Our duty with regard to errors is not to revive them, but simply to forget them.” So much for the history of economic thought. 7
And contemporary courses in economics have taken Say’s dictum to heart and made it their business to exclude past errors. And that's why you don't actually have any study, really, of economic thought in most economic curriculum today, because they would be the study of mistakes. And we've transcended those mistakes, haven't we? That's why we never have any crashes. [laughter]
Now, but the point of studying history of economic thought is precisely to realize that the important debates in economics have never been resolved, and continue to vex us today. Is the quantity theory of money true? Is it true that state spending is inherently wasteful? Economists have always been divided on such issues, and the different contemporary schools are heirs to these disputes. To sanitize them by delivering a mainstream textbook account or opinion is to rob the subject of its richness, diversity, and ability to illuminate reality. Knowledge of the history of economic thought can help us avoid hubris, or absolute confidence in our own favored school of thought, be it neoclassical or post-Keynesians. So economists shouldn't aim for a comprehensive, universal and timeless theory, but must try to keep up with and understand a continually changing system.
Studying history makes it clear that the truth of economic propositions depends on the context in which they are applicable. For example, can anyone doubt that the Keynesian revolution arose out of the circumstances of the Great Depression? Can anyone doubt that Friedman's monetarism was a reaction to the inflation of the 1970s?
To take a less obvious example, and this I think, is controversial. The marginalist revolution of the 1870s was part of an attempt to refute Marx's labor theory of value. And the notion that the factors of production are paid their marginal product was a very useful affirmation of the value of the businessman to society.
Finally, history shows us how economic ideas reflect power structures. Can one reasonably doubt that financial theory reflects the interests of the banking system in freeing itself from state regulation?
So let me end with a final thought. progress in economics is not from the particular to the general, I think that's a big mistake. We don't start with partial and incomplete theories, which evolve through a process of maths to ever more general theories, which contain progressively more of the truth about economic life. That's the model of a natural science. That is not how economics works. It's never been true of economics.
I would like to champion the view of horses for courses, for choosing those bits of economics appropriate to different problems and situations without any presumption that one approach is superior to others. For example, development economics requires relatively little maths, because the real problem has to do with government and governance.
On the other hand, if you want to forecast the conditions of supply and demand for a particular product, or a particular sector of the economy, then maths is very helpful and useful, and indeed essential. So there is there is a case for mathematical microeconomics. In fact, it's very important. But having said that, the banishing of history from standard economics curricula is a symptom of a loss of pluralism and imagination in the discipline. It's become complacent. It's become archaic in many, many of its intellectual structures. Students now leave universities thinking there's only one way to do economics, the way they've been taught in years one, two, and three. And this lack of diversity leads to intellectual arrogance. Economists treat anyone who doesn't do economics in their way as somehow inferior, they may be politely condescending [laughter], but the condescension is undoubtedly there, and I expect the condescension to be polite this evening. [laughter & applause]
Awareness of the past should make our discipline less arrogant, and more useful.
Thank you.
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