What if people produced goods to obtain money, not merely as a transactional device to be swiftly exchanged for other things, but as a store of value, to be held indefinitely? 如果人们生产商品是为了得到钱，不仅是把它作为一种能被迅速用来交换其他东西的交易手段，而且是作为一种可以无限期持有的价值储备手段？

　　A widespread propensity to hoard money posed a problem for Say's vision. 一种广泛的囤钱倾向给萨伊的愿景带来了一个问题。

　　It interrupted the exchange of goods for goods on which his theory relied. 它中断了他的理论一直为依据的物物交换。

　　Unlike the purchase of newly created products,  与对刚生产出来的产品的购买所不同的是，

　　the accumulation of money provides no stimulus to production (except perhaps the mining of precious metals under a gold or silver standard). 钱的累积对生产提供不了任何刺激（也许在金本位制或者银本位制之下的贵金属开采是个例外）。

　　And if, as he had argued, an oversupply of some commodities is offset by an undersupply of others,  再者，如其所言，如果某些商品的供给过剩因为其他商品的供给不足而得以抵消；

　　then by the same logic, an undersupply of money might indeed entail an oversupply of everything else. 那么，据此逻辑，钱的供给不足或许真就造成其他所有东西的供给过剩。

　　Say recognised this as a theoretical danger, but not a practical one. 萨伊承认，这是一种理论上的，而不是实践中的风险。

　　He did not believe that anyone would hold money for long. 他不相信人们会长久地持有货币。

　　Say's own father had been bankrupted by the collapse of assignats, paper money issued after the French Revolution. 萨伊的父亲曾经因为法国大革命后发行的纸币——纸券的崩溃而破产。

　　Far from hoarding this depreciating asset, people were in such a rush to spend it, that “one might have supposed it burnt the fingers it passed through.” 人们当时不仅不囤积这种日复一日地贬值的资产，而且还如此匆忙地把它花掉，以至于“人们可能会认为这种钱过手就会烧了手指一样。”

　　In principle, if people want to hold more money, a simple solution suggests itself: print more. 从理论上来说，如果人们想持有更多的钱，一种简单的解决办法就自己浮出水面：印制更多的钱。

　　In today's world, unlike Say's, central banks can create more money (or ease the terms on which it is obtainable) at their own discretion. 在当今世界，与萨伊的世界所不同的是，央行能够自行决定印制更多的钱（或者是放宽其赖以得到的各种条款）。

　　This should allow them to accommodate the desire to hoard money, while leaving enough left over to buy whatever goods and services the economy is capable of producing. 这应当能让它们在化解囤钱的渴望的同时，留出足够的钱去购买经济体能够生产的任何商品和服务。

　　But in practice, even this solution appears to have limits, judging by the disappointing results of monetary expansions since the financial crisis of 2007-08. 但是，在实践中，根据2007-08年的金融危机以来的令人大失所望的货币扩张结果来判断，即便是这种解决方案似乎也有限的。

　　Today, many people scoff at Say's law even before they have fully appreciated it. 如今，许多人甚至在全面理解萨伊定律之前就嘲笑它。

　　That is a pity. 这既可悲又可叹。

　　He was wrong to say that economy-wide shortfalls of demand do not happen. 萨伊错就错在认为经济体的全面需求不足不会发生这件事上。

　　But he was right to suggest that they should not happen. 但是，在指出它们不应当发生这方面，他是对的。

　　Contrary to popular belief, they serve no salutary economic purpose. 与大众信念相反的是，它们服务于一无益处的经济目的。

　　There is instead something perverse about an economy impoverished by lack of spending. 反而倒是有经济体因为开支缺乏而致贫这种拙拙怪事。

　　It is like a subsistence farmer leaving his field untilled and his belly unfilled, farming less than he'd like even as he eats less than he'd choose. 这就像是自给自足经济下的农民纵然吃不上想吃的也会让田地荒在那里、让肚子填不饱一样。

　　When Say's law fails to hold, workers lack jobs because firms lack customers, and firms lack customers because workers lack jobs. 当萨伊定律站不住脚的时候，工人因为公司缺乏客户而缺乏工作，公司因为工人缺乏工作而缺乏客户。

　　Say himself faced both a ruinous shortage of demand for his cotton and excess demand for his treatise. 萨伊自己就同时遇上了对他棉布需求的严重短缺和对他著作的过度需求这两件事。

　　The first edition sold out quickly; Napoleon blocked the publication of a second. 他的著作的第一版很快销售一空；拿破仑阻止了第二版的发行。

　　Eventually, Say was able to adapt, remixing his activities as his own theory would prescribe. 最后，萨伊能够适应形势，按照他自己的理论所说，重新调整了他的行为。

　　He quit his cotton mill in 1812, notes Mr Schoorl. 斯库尔写道，1812年，他卖掉了棉纺厂。

　　And within weeks of Napoleon's exile in 1814, he printed a second edition of his treatise (there would be six in all). 1814年，在拿破仑被流放的几周内，他刊印了自己著作的第二版（总共会有6版）。

　　In 1820 he began work once again at the Conservatory in Paris—not this time as a student of spinning,  1820年，他再次开始在巴黎工艺美院工作——这次不是以一名纺织学生的身份，

　　but as France's first professor of economics, instructing students in the production, distribution and consumption of wealth. 而是作为法国的首席经济学教授，在财富的生产、分配和消费等方面指导学生。

　　He considered it a “new and beautiful science”. 他认为这是一门“全新、美丽的科学”。

　　And, in his hands, it was. 在他手里，的确如此。