Restrictions on international trade, primarily non-tariff barriers, have multiplied rapidly in the 1980s. In the third article in this Review, “An Introduction to Non-Tariff Barriers to Trade,” Cletus C. Coughlin and Geoffrey E. Wood provide a primer on these barriers. The authors begin by identifying numerous non-tariff barriers and document their proliferation. The general effects of non-tariff barriers, like those of tariff barriers, are to increase the domestic prices of the protected goods and to impede trade to benefit selected producers at the expense of domestic producers. Numerous reasons for the increasing use of non-tariff instead of tariff barriers are provided. Among the reasons are their more certain protective effects, the possibility that some benefits can be captured by foreign producers and domestic politicians and the fact that their adverse effects are generally less obvious to consumers. To date, attempts through the General Agreement on Tariffs and Trade (GATT) to counteract the expansion of non-tariff barriers have met with little success. A brief history of these attempts completes the paper.