Trade barriers are government-induced restrictions on international trade. Most trade barriers work on the same principle: the imposition of some sort of cost (money, time, bureaucracy, quota) on trade that alters the price or availability of the traded products. Barriers take the form of tariffs (which impose a financial burden on imports) and non-tariff barriers to trade (which uses other overt and covert means to restrict imports and occasionally exports). Trade barriers have been criticized for their negative impacts on consumers and their unequal applications to developing countries.
The use of trade barriers has shifted throughout history. Protectionist policies were commonplace in the mercantilist era, but a combination of industrialization and liberalization led to a shift towards free trade in the mid-to-late 19th century. The interwar period led to a regression back to protectionism, but post-WWII there was a near-universal commitment to multilateralism and the creation of international organizations that led to lower tariffs and decreased protectionism. While organizations like the World Trade Organization still provide an avenue for trade negotiations, in recent times there has been a shift away from trade openness and towards plurilateral agreements and regionalism.
