The data show a definite statistical link between freer trade and economic growth. Economic theory points to strong reasons for the link. All countries, including the poorest, have assets — human, industrial, natural, financial — which they can employ to produce goods and services for their domestic markets or to compete overseas. Economics tells us that we can benefit when these goods and services are traded. Simply put, the principle of “comparative advantage” says that countries prosper first by taking advantage of their assets in order to concentrate on what they can produce best, and then by trading these products for products that other countries produce best.