What is unique about international trade? This is the question that I pose to my two trade classes (Econ 390: International Economics and Econ 385: International Economic Policy) every day this Fall. This question is crucial toward understanding the content in the courses.
In Econ 390, the more technical of the two courses, we’re using Paul Krugman, Maurice Obstfeld, and Marc Melitz’s textbook International Economics (among others). The opening chapters deal with the main models of trade theory: Ricardian, Specific-Factors, Hecksher-Ohlin, and the combined Standard Trade Model.
As with any good model, we start with the simple case of two people. How does the model develop here? What are the driving forces of change and outcomes? What are the impacts of the assumptions? We then expand the model into the world of international trade.
When we expand the model outward, we notice something interesting: nothing unique happens when the model is expanded to include international trade. The factors adjusting income distribution stay the same. The influences governing specialization stay the same. The key for any of these models is that a change in relative prices changes the distribution of income and economic activity. This result is no different than microeconomic outcomes. Any change in relative prices, regardless of whether this occurs because of domestic or international conditions, will cause changes in the economy. This is a point Krugman et al repeatedly stress in their textbook and a point I repeatedly stress as well.
Let’s take, for example, the Specific-Factors model, which argues that in any form of production, there are some factors of production specific to that production and some factors that are mobile and thus can switch from one form of production to the other. If there is some relative price change, the model predicts the domestic owners of the specific factor of the now relatively-expensive good will benefit (increased income), the domestic owners of the specific factor of the now relatively-inexpensive good will not benefit (less income) and the domestic owners of the mobile factor will have an ambiguous impact. Note that it doesn’t matter if this change in relative prices is caused by domestic issues (say, a tax on one good that changes its relative price) or by international trade (a change in world price). The effect is the same.
So, what then is unique about international trade? Is it that differing legal regimes between countries have a major impact and thus people should be upset about that? This doesn’t hold, especially in the United States, as each of the 50 states has different legal rules and regulations. California, for example, has very stringent rules about labeling and selling; New Hampshire, not so much. New Hampshire thus has an advantage over California, but people in California aren’t protesting New Hampshire products. So, the uniqueness of international trade cannot rest on differing legal regimes.
Dani Rodrik suggests its a perception of unfairness due to different “domestic norms” and “social understandings” that is unique. While the perception may be unique, the actual reality of any unfairness due to these differences is not unique. Again, domestic norms and social understandings are legion among the various regions of the United States. Some states have stronger social safety nets than others. Firms will move to take advantage of less costly regulations. So, this difference in social understandings is not unique to international trade, either.
There are many other excuses people can give for the uniqueness of international trade and why tariffs are justified internationally but not nationally; I’ve just listed two. But the same analysis should be performed for each of these excuses. You’ll find they do not hold up.
In short, there is nothing economically or socially unique about international trade that renders it subject to special rules and regulations.