List and describe the four basic types of trade barriers.

The four basic types of trade barriers are:(1)tariffs: a tax imposed by a nation on imports. Tariffs may be used to collect revenue for the government, or they may be protective tariffs that are designed to shield domestic producers from foreign competition. (2)import quotas: a limit imposed by a nation on the quantity (or total value)of a good that may be imported during some time period. (3)nontariff barriers: refers to all barriers other than protective tariffs that nations erect to impede international trade, including import quotas, licensing requirements, unreasonable product-quality standards, or unnecessary bureaucratic detail in customs procedures. (4)voluntary export restrictions: a voluntary limitation by countries or firms of their exports to a particular foreign nation. These are undertaken to avoid the enactment of formal trade barriers by the foreign nation.