The Comparative Advantage Theory, proposed by David Ricardo, suggests that countries should specialize in producing and exporting goods in which they have a lower opportunity cost compared to other countries.

The Absolute Advantage Theory, introduced by Adam Smith, states that countries should focus on producing and exporting goods for which they have lower absolute production costs compared to other countries.

The Heckscher-Ohlin Model, developed by Eli Heckscher and Bertil Ohlin, emphasizes the role of differences in factor endowments, such as labor skills, capital abundance, and natural resources, in determining patterns of international trade.

According to the Heckscher-Ohlin Model, countries tend to export goods that require intensive use of factors of production that are relatively abundant in their economies.

The Gravity Model in international trade incorporates the effects of transportation costs and geographic distance on the volume of trade between countries.

The Stolper-Samuelson Theorem suggests that free trade can lead to changes in the relative prices of factors of production, benefiting owners of abundant factors and potentially harming owners of scarce factors.

The New Trade Theory, developed by Paul Krugman and others, emphasizes the role of economies of scale, increasing returns, and imperfect competition in shaping patterns of international trade.

The New Trade Theory suggests that countries tend to specialize in producing goods that exhibit increasing returns to scale, leading to potential gains from trade even in the absence of traditional comparative advantage.

The Linder Hypothesis proposes that countries tend to export goods that are similar to goods they import, reflecting similarities in consumer preferences and production capabilities.

The Political Economy of Trade explores the role of government policies, institutions, and political factors in shaping patterns of international trade and the distribution of gains from trade.

The Infant Industry Argument suggests that temporary protection of domestic industries can be justified to allow them to mature and become competitive in the global market.

Dumping in international trade involves selling goods in a foreign market at a price below the cost of production or below the price charged in the domestic market.

The terms of trade in international trade represent the ratio of export prices to import prices, indicating the amount of imports a country can obtain for a given amount of exports.

The Endogenous Growth Theory explores the role of technological change and innovation as drivers of economic growth and their impact on international trade patterns.

A trade deficit in international trade occurs when the value of a country's imports exceeds the value of its exports.