Final answer:
Economic gains can be achieved through intra-industry trade, which allows countries to specialize according to comparative advantage and benefit from a wider array of goods. Countries export and import the same goods, like cars, to optimize production and consumption, facilitating economic growth.
Step-by-step explanation:
There can be economic gains for a country from both importing and exporting goods, such as cars, due to the concept of intra-industry trade. This occurs when a country is both a substantial exporter and importer of the same category of goods. For example, the United States exports and imports cars, taking advantage of the theory of comparative advantage which suggests that countries should specialize in producing certain goods that they can produce more efficiently and trade for other goods.
Intra-industry trade allows countries to offer a wider variety of goods for consumers, and can lead to gains from trade as different models or grades of products are exchanged. Along with comparative advantage, another reason for such trade can be the presence of multinational corporations which may import parts, assemble them, and then export finished products. The United States, for instance, exported around $146 billion worth of autos, and imported around $327 billion worth of autos in a given year, showing that a significant portion of trade can be within the same industry. This type of trade can optimize production and consumption patterns, leading to economic growth.