Six Big Ideas: Overcapacity and undercapacity 六大经济学理论：产能过剩和产能不足

　　Glutology 过剩的学问

　　The third brief in our series on big economice ideas looks at Say's law 我们有关重大经济思想系列的第三篇文章考察的是萨伊定律。

　　In 1804 Jean-Baptiste Say enrolled in the National Conservatory of Arts and Crafts in Paris to learn the principles of spinning cotton. 1804年，让·巴蒂斯特·萨伊在巴黎国民工艺美院报名入学，学习纺织棉花的原理。

　　The new student was 37 years old, points out his biographer, Evert Schoorl,  他的传记作者艾佛特·斯库尔 （Evert Schoorl）指出，这名新学生当时已经37岁，

　　with a pregnant wife, four children and a successful career in politics and letters trailing behind him. 有一位已经怀孕的妻子、4个孩子以及在政界和文坛的功成名就。

　　To resume his studies, he had turned down two lucrative offers from France's most powerful man, Napoleon Bonaparte. 为了重新开始学习，他已经拒绝了来自当时法国最有权势的人——拿破仑·波拿巴的两次厚邀。

　　The ruler would have paid him handsomely to write in support of his policies. 这位统治者本来要重金聘请他，让他撰写支持他的政策的文章。

　　But rather than “deliver orations in favour of the usurper”, Say decided instead to build a cotton mill, spinning yarn not policy. 但是，萨伊不但没有“发表美化这位篡位者的文章”，反而决定建造一座棉纺厂，纺纱织布，而不是制定政策。

　　Napoleon was right to value (and fear) Say's pen. 拿破仑重视（并害怕）萨伊的这支笔是对的。

　　As a pamphleteer, editor, scholar and adviser, he was a passionate advocate for free speech, trade and markets. 作为一名小册子作者、编辑、学者和顾问，他是一位自由言论、自由贸易和自由市场的热情支持者。

　　He had imbibed liberal principles from his heavily annotated copy of Adam Smith's "The Wealth Of Nations” and bolstered his patriotic credentials in battle against Prussian invaders.  他从他那本满是注释的亚当·斯密的《国富论》的书中汲取了自由原则，并在抗击普鲁士入侵者的战斗巩固了他的爱国者声誉

　　(During breaks in the fighting, he discussed literature and political economy with other learned volunteers “almost within cannonballs' reach”. ) （在战斗间隙，他曾与其他几位博学的自愿者“几乎是在炮弹射程之内”，讨论文学和政治经济学。）

　　His greatest work was “A Treatise on Political Economy”, a graceful exposition (and extension) of Smith's economic ideas. 他最伟大的作品是《政治经济学概论》（A Treatise on Political Economy），这是一部对亚当·斯密的经济学思想做出了优雅的阐释(和扩充)的著作。

　　In Say's time, as nowadays, the world economy combined strong technological progress with fitful demand, spurts of innovation with bouts of austerity. 在萨伊那个时代，如同现在一样，世界经济集强大的技术进步与断断续续的需求、创新的迸发与紧缩的发作于一身。

　　In France output of yarn grew by 125% from 1806 to 1808, when Say was starting his factory. 就在萨伊创办自己的工厂时，法国的纱线产出在1806年到1808年间增长了125%。