【原】大卫·李嘉图

        中译文：

       自从英国经济学家大卫·李嘉图于1817年提出理论基础以来，经济方面的权威书籍就已经向世人展示：自由贸易能改善交易双方的生活水平。所谓自由贸易，就是在贸易过程中免除关税、配额、补贴，以及排除政府干扰的贸易。美国的政策则充分地体现了这一理论。为什么说自由贸易具有普惠性呢？对此，一个所谓比较优势理论作出了回答。

在这里，打个简单的比方：假如一个外科医生既精于手术，又善于血常规检测，那么一个更为有效的方法就是让这个外科医生集中精力做手术，而雇用一个医技稍差的做血检，这样，这名外科医生就可以充分高效地利用她自己的时间了。

由此类推，即使美国既精于高端生物技术，又善于常规药品生产，可是，如果美国能够把药品生产让给别的国家来做，而这些国家又能降低药品成本，岂不是好事？这样，美国既可以从廉价的产品中获益，又能把自己有限的资源投向更有价值的事业上，这无论如何都不失为两全其美的好事。不过，美国经济学家保罗·萨缪尔森对此却不以为然：怎么办？假使低收入的国家也掌握了高端产业。

他推算：假如让美国的工人把足够多的薪水较高的工作让给别的国家的工人，那么我们从低廉的价格中所获的利益，可能就补偿不了我们因购买力下降所造成的损失。

 “自由贸易不总是呈现双赢的局面,” 萨缪尔森得出结论。尤其是在当今的世界，他说，自由贸易会给美国带来麻烦，因为工资较低的大国，象印度和中国，正日益能够生产几乎所有美国产品，或者说提供几乎所有美国服务。

假如美国和他们进行自由贸易，那么，他们非常低的平均工资水平会有所上升，而我们的则会有所下降。他推算：虽说美国经济仍然可能有所发展，但发展的速度会相对缓慢得多。

原文：

　　Ever since the economist David Ricardo offered the basic theory in 1817, economic scripture has taught that open trade—free of tariffs, quotas, subsidies or other government distortions—improves the well-being of both parties. U.S. policy has implemented this doctrine with a vengeance. Why is free trade said to be universally beneficial? The answer is a doctrine called “comparative advantage”.

　　Here’s a simple analogy. If a surgeon is highly skilled both at doing operations and performing routine blood tests, it’s more efficient for the surgeon to concentrate on the surgery and pay a less efficient technician to do the tests, since that allows the surgeon to make the most efficient use of her own time.

　　By extension, even if the United States is efficient both at inventing advanced biotechnologies and at the routine manufacture of medicines, it makes sense for the United States to let the production work migrate to countries that can make the stuff more cheaply. Americans get the benefit of the cheaper products and get to spend their resources on even more valuable pursuits, That, anyway, has always been the premise. But here Samuelson dissents. What if the lowerwage country also captures the advanced industry?

　　If enough higher-paying jobs are lost by American workers to outsourcing, he calculates, then the gain from the cheaper prices may not compensate for the loss in U.S. purchasing power.

　　“Free trade is not always a win-win situation,” Samuelson concludes. It is particularly a problem, he says, in a world where large countries with far lower wages, like India and China, are increasingly able to make almost any product or offer almost any service performed in the United States.

　　If America trades freely with them, then the powerful drag of their far lower wages will begin dragging down U.S. average wages. The U.S. economy may still grow, he calculates, but at a lower rate than it otherwise would have.