Điều thú vị từ lý thuyết lợi thế tuyệt đối và lợi thế so sánh

Đây là điều thú vị khi đọc lại cuốn principle of economics của Mankiw. Ngày xưa, sinh viên lại không chú ý tới những điểm ngoài lề như thế này.
Adam Smith put the argument: " It's a maximum of every prudent master of family, ......"
This quotation is from Smith's 1776 book: An inquiry into the Nature and Causes of the Wealth of Nations, which was a landmark in the analysis of trade and economic interdependence.
Smith's book inquired David Ricardo, a milionare stock-broker, to become an economist. In his 1817 book Principles of Political Economy and Taxation, Ricardo developed the principle of comparative advantage as we know today. ......... Ricardo's theory is starting point of modern international economics, but his defense of free trade was not a mere academic exercise. Ricardo put his beliefs to work as a member of the British Parliament, where he opposed the Corn Laws, which restricted the import of grain.
 The conclusions of Smith and Ricardo on the gains from trade have held uo well over time. Although economist often disagree on question of policy but they are united in their support of free trade. Morever, the central agurment for free trade has not changed much in the past two centuries. Even though the field of economics has brodened it's scope and refined its theories since the time of Smith and Ricardo, economists's opposition to trade restrictions is still based largely on the principle of comparative advantage.
------------
This quotation is from Mankiw's book: The principles of economics at page 57.