Tariffs are similar to tolls, which are applied to people rather than goods.
Tax, tariff and trade rules in modern times are usually set together because of their common impact on industrial policy, investment policy and agricultural policy. A trade bloc is a group of allied countries agreeing to minimize or eliminate tariffs against trade with each other, and possibly to impose protective tariffs on imports from outside the bloc. A customs union has a common external tariff, and, according to an agreed formula, the participating countries share the revenues from tariffs on goods entering the customs union.
If a country's major industry collapses due to foreign competition, the loss of jobs and tax revenue can severely impair parts of that country's economy. Protective tariffs have been used as a measure against this possibility. However, protective tariffs have disadvantages as well. The most notable is that they increase the price of the good subject to the tariff, disadvantaging consumers of that good or manufacturers who use that good to produce something else: for example a tariff on food can increase poverty, while a tariff on steel can make automobile manufacture less competitive. They can also backfire if countries whose trade is disadvantaged by the tariff impose tariffs of their own, resulting in a trade war and disadvantaging both sides.
Some economic ideologies hold that tariffs are a harmful interference with the laws of the free market. They believe that it is disadvantageous for a country to artificially maintain an inefficient industry, and that it is better to allow it to collapse and to allow a new one to develop in its place. The opposition to all tariffs is called the free trade principle; the World Trade Organization aims to reduce tariffs and to avoid countries discriminating between other countries when applying tariffs .
There are two mains ways of implementing a tariff:
- An ad valorem tariff is a fixed percentage of the value of the good that is being imported. Sometimes these are problematic as when the international price of a good falls, so does the tariff, and domestic industries become more vulnerable to competition. Conversely when the price of a good rises on the international market so does the tariff, but a country is often less interested in protection when the price is higher. They also face the problem of transfer pricing where a company declares a value for goods being traded which differs from the market price, aimed at reducing overall taxes due.
- A specific tariff is a tariff of a specific amount of money that does not vary with the price of the good. These tariffs may be harder to decide the amount at which to set them, and they may need to be updated due to changes in the market or inflation.
Adherents of supply-side economics sometimes refer to domestic taxes, such as income taxes, as being a tariff affecting inter-household trade.
