Tariff
In contrast, in economic theory tariffs are viewed as a primary element in international trade with the function of the tariff being to influence the flow of trade by lowering or raising the price of targeted goods to create what amounts to an artificial competitive advantage. When tariffs are viewed and used in this fashion, they are addressing the country's and the competitors' respective economic healths in terms of maximizing or minimizing revenue flow rather than in terms of the ability to generate and maintain a competitive advantage which is the source of the revenue. As a result, the impact of the tariffs on the economic health of the country are at best minimal but often are counter-productive.
Tariff
Trade deficits mean that consumers buy too much foreign goods and too few domestic products. According to Keynesian theory, trade deficits are harmful. Countries that import more than they export weaken their economies. As the trade deficit increases, unemployment or poverty increases and GDP slows down. And surplus countries getting richer at the expense of deficit countries. They destroy the production of their trading partners. John Maynard Keynes thought that surplus countries should be taxed to avoid trade imbalances. The tariff is used to equalize the trade balance in order to protect domestic workers. Peter Temin explain that "a tariff is an expansionary policy, like a devaluation as it diverts demand from foreign to home producers".