Final answer:
Countries can gain economically from importing and exporting the same goods through specialization and trade, which leads to economies of scale, increased competition, innovation, and a wider variety for consumers.
Step-by-step explanation:
Economic gains for a country from both importing and exporting the same good, such as cars, can be explained by specialization and trade. This process is facilitated by the concept of intra-industry trade, where nations focus on producing specific types of goods within an industry in which they have a comparative advantage and then trade with other nations that specialize in different types of similar goods. For example, a country might export luxury cars it specializes in producing, while importing fuel-efficient cars that another country produces more efficiently.
Moreover, trade can lead to economies of scale, with larger companies able to produce at lower average costs due to higher production volumes. This allows for competitive pricing, innovation, and variety, benefiting consumers. Such trade patterns are seen not only internationally but also between states within a country, demonstrating the universal value of competition and trade.