We live in a world where trade policies are liberal and immigration policies are
restrictive. Recent globalization discussions give the impression that this policy difference is a modern phenomenon (Wellisch and Walz 1998; Hillman and Weiss 1999), implying that trade policy was liberal and open a century ago. This conventional view is quite wrong. Instead, while most labor-scarce economies today have open trade and closed immigration policies, a century ago the labor-scarce economies had just the opposite, open immigration and closed trade policies. Thus, the inverse policy correlation has persisted over almost two centuries.
Why have policies towards the movement of labor and goods always been so different in labor-scarce economies? After all, importing labor-intensive products is pretty much like importing labor. So shouldn’t trade and migration policies reinforce each other? Consider for a moment the simple 2×2×2 model in which trade is driven by factor endowments. Furthermore, let us think about the country where labor is relatively scarce since that’s the country for which immigration policies matter. Suppose such a country puts up a tariff to protect the scarce factor, labor. In the absence of immigration, wages will increase. But if labor is allowed to move across borders, the tariff-induced wage increase will be undone by immigration (Mundell 1957). By the same logic, an immigration policy designed to protect domestic labor will be undone by free trade: the desired effect will only be achieved by restricting both trade and immigration. Simple theory predicts that immigration and import restriction should go together. In fact, they never have. Therein lies the policy paradox.