Not only has the ratio of international trade in goods and services to world GDP risen steadily over the past half-  1  2 3  2  Much of what is assembled in final salable form in the United States, for example, may consist of components from many continents.
Companies seek out the lowest costs of inputs to effectively compete for their customers' dollars. This international competition, left unfettered, history suggests, would tend to direct output to the comparatively most efficient producers of specific products or services and, hence, maximize standards of living of all participants in trade.