There are many ways by which national government regulate international trade. Some of these are tariffs, quotas, voluntary export restraints, antidumping duties, as well as technical, administrative, and other regulations. An import tariff is simply a tax on import. As such, it increases prices to domestic consumers, reduces the quantity demanded of the commodity at home and imports from abroad, and encourages the domestic production of import substitutes. The nation also collects tariff revenues. This is seen by examining Figure 12-4 (which is an extension of Figure 9-4).