Defending Against Skeptics:
The True Meaning and Intuition of the Theory of Comparative Advantage

Many people who learn about the theory of comparative advantage quickly convince themselves that its ability to describe the real world is extremely limited, if not non-existent. Although the results follow logically from the assumptions, the assumptions are easily assailed as unrealistic. For example, the model assumes only two countries producing two goods using just one factor of production. There is no capital or land or other resources needed for production. The real world, on the other hand, consists of many countries producing many goods using many factors of production. Each market is assumed to be perfectly competitive, when in reality there are many industries in which firms have market power. Labor productivity is assumed fixed, when in actuality it changes over time, perhaps based on past production levels. Full employment is assumed, when clearly workers cannot be immediately and costlessly moved to other industries. Also, all workers are assumed identical. This means that when a worker is moved from one industry to another, he or she is immediately as productive as every other worker who was previously employed there. Finally, the model assumes that technology differences are the only differences that exist between the countries.

With so many unrealistic assumptions it is difficult for some people to accept the conclusions of the model with any confidence, especially when so many of the results are counterintuitive. Indeed one of the most difficult aspects of economic analysis is how to interpret the conclusions of models. Models are, by their nature, simplifications of the real world and thus all economic models contain unrealistic assumptions. Therefore, to dismiss the results of economic analysis on the basis of unrealistic assumptions means that one must dismiss all insights contained within the entire economics discipline. Surely, this is not practical or realistic. Economic models in general and the Ricardian model in particular do contain insights that most likely carry over to the more complex real world. The following story is meant to explain some of the insights within the theory of comparative advantage by placing the model into a more familiar setting.

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