历史上经济学家论:供给与需求。凯恩斯认为:“有效需求不足,常常阻碍生产”,“有效需求不足常常可能妨碍经济繁荣”(《就业利息与货币通论》凯恩斯著)马克思说:“要给需求与供给这两个概念下一般的定义,真正困难在于它们好像只是同义反复”(资本论:马恩全集13-206) 萨伊:(西方经济学家)在1803年出版的《政治经济学概论》中,他说:当产品在市场上滞销时,就常常听到人说,“困难不在生产,而在销售,认为是银根紧。但若问如何刺激销路,活跃消费时,却是大多数人都说不清楚,实际上市场上的买卖都是以产品购买产品 Historians economists on: supply and demand. Keynes argued that “insufficient effective demand often hinders production,” and “insufficient effective demand can often hamper economic prosperity” (Keynes, Employment and Money). Marx said: “Given the two concepts of demand and supply, Definition, the real difficulty is that they seem to be synonymous with repetition. ”(Capitalism: Complete Works of Mann 13-206) Saiy: (Western Economist) In his Introduction to Political Economy, published in 1803, he said: When the market is slow-moving, people are often told to say, "The difficulties are not production, but sales are considered as tight-knit ones. But when asked how to stimulate sales and active consumption, most people can not tell. In fact, Buying and selling in the market is based on products purchased products