It can also be seen that the US was the biggest exporter of machinery, nuclear reactors and boilers. This is in line with the theory of comparative advantage that propounds that an economy should specialize in the production of that product in which it has a competitive advantage. In the terminology of economics, the basic propositions of the law of comparative advantage refer to the capability of an economy to produce a type of good/service at a comparatively lower marginal cost as well as opportunity cost in contrast to the other party. Unlike the theory of absolute advantage that directs the entire focus on the capability of the economy to manufacture a particular type of good in a manner that lowers the absolute cost in contrast to the other economy, the theory of comparative advantage highlights the fact that trade can lead to value creation for both the economies even in the scenario when one economy can manufacture products with fewer resources in comparison to the other. This is on account of the differing opportunity costs of the resources.