In reality, much trade protection has little to do with the arguments just described. Instead, it reflects the political influence of import-competing producers.

We’ve seen that a tariff or import quota leads to gains for import-competing producers and losses for consumers. Producers, however, usually have much more influence over trade policy decisions. The producers who compete with imports of a particular good are usually a smaller, more cohesive group than the consumers of that good.

An example is trade protection for sugar: the United States has an import quota on sugar, which on average leads to a domestic price about twice the world price. This quota is difficult to rationalize in terms of any economic argument. However, consumers rarely complain about the quota because they are unaware that it exists: because no individual consumer buys large amounts of sugar, the cost of the quota is only a few dollars per family each year, not enough to attract notice. But there are only a few thousand sugar growers in the United States. They are very aware of the benefits they receive from the quota and make sure that their representatives in Congress are also aware of their interest in the matter.

Given these political realities, it may seem surprising that trade is as free as it is. For example, the United States has low tariffs, and its import quotas are mainly confined to clothing and a few agricultural products. It would be nice to say that the main reason trade protection is so limited is that economists have convinced governments of the virtues of free trade. A more important reason, however, is the role of international trade agreements.