demand curve and above the price of the good. Producer surplus is the difference between the minimum amount for which a producer is willing to sell his product and the price which he actually receives. Geometrically, producer surplus is equal to the area above the supply curve and below the price line. These tools are fundamental to the student's understanding of the implications of trade policies and should be developed carefully.
The costs of a tariff include distortionary efficiency losses in both consumption and production. A tariff provides gains from terms of trade improvement when and if it lowers the foreign export price. Summing the areas in a diagram of internal demand and supply provides a method for analyzing the net loss or gain from a tariff.
Other instruments of trade policy can be analyzed with this method. An export subsidy operates in exactly the reverse fashion of an import tariff. An import quota has similar effects as an import tariff upon prices and quantities but revenues, in the form of quota rents, accrue to foreign producers of the protected good. Voluntary export restraints are a form of quotas in which import licenses are held by foreign governments. Local content requirements raise the price of imports and domestic goods and do not result in either government revenue or quota rents.
Throughout the chapter the analysis of different trade restrictions are illustrated by drawing upon specific episodes. Europe's common agricultural policy provides and example of export subsidies in action. The case study corresponding to quotas describes trade restrictions on U.S. sugar imports. Voluntary export restraints are discussed in the context of Japanese auto sales to the United States. The oil import quota in the United States in the 1960's provides an example of a local content scheme.
There are two appendices to this chapter. Appendix I uses a general equilibrium framework to analyze the impact of a tariff, departing from the partial equilibrium approach taken in the chapter. When a small country imposes a tariff, it shifts production away from its exported good and toward the imported good. Consumption shifts toward the domestically produced goods. Both the volume of trade and welfare of the country declines. A large country imposing a tariff can improve its terms of trade by an amount potentially large enough to offset the production and consumption distortions. For a large country, a tariff may be welfare improving.
Appendix II discusses tariffs and import quotas in the presence of a domestic monopoly. Free trade eliminates the monopoly power of a domestic producer and the monopolist mimics the actions of a firm in a perfectly competitive market, setting output such that marginal cost equals world price. A