A monopoly is a market structure where a single seller controls the entire market, giving them significant market power and the ability to set prices and output levels.

In an oligopoly, firms are interdependent because their decisions, such as pricing and output levels, affect each other's profits. This interdependence is analyzed using game theory, which provides a framework for understanding strategic interactions among firms.

A tariff is a tax imposed on imported goods, increasing their price in the domestic market. Tariffs are often used to protect domestic industries from foreign competition or to generate revenue for the government.

Comparative advantage refers to the ability of a country to produce a good or service at a lower opportunity cost compared to other countries. According to the theory of comparative advantage, countries should specialize in producing and exporting goods for which they have a comparative advantage.

A free trade agreement (FTA) is an agreement between two or more countries to reduce or eliminate tariffs and other trade barriers, facilitating the free flow of goods and services between them.

Economies of scale occur when the average cost of production decreases as the quantity produced increases. This can be due to factors such as specialization, division of labor, and technological improvements.

In a perfectly competitive market, firms are price takers, meaning they have no control over the market price. They must accept the prevailing market price and adjust their output accordingly.

A quota is a trade policy that restricts the quantity of a good that can be imported. Quotas are often used to protect domestic industries from foreign competition or to manage the balance of payments.

Product differentiation refers to the situation where goods or services are not perfect substitutes for each other. Instead, they have unique characteristics or attributes that make them distinct from competing products.

In a monopolistically competitive market, firms have some degree of market power due to product differentiation. This allows them to set prices above marginal cost and earn positive economic profits.

An embargo is a trade policy that prohibits the import or export of certain goods. Embargoes are often used for political or economic reasons, such as punishing a country for its actions or protecting domestic industries.

Externalities are costs or benefits that arise from the production or consumption of a good or service that are not reflected in the market price. Social costs are negative externalities that impose costs on society as a whole.

A duopoly is a market structure characterized by the presence of only two sellers. Duopolies often exhibit strategic interactions between the two firms, such as price wars or collusion.

A subsidy is a trade policy that involves providing financial assistance to domestic industries to make them more competitive. Subsidies can take various forms, such as direct cash payments, tax breaks, or low-interest loans.

Dumping is a trade practice where a company exports goods to a foreign market at a price below the cost of production. Dumping can be used to gain market share or to harm competing domestic industries.