The three reasons for trade are: 1. To take advantage of comparative advantage: This is the most fundamental reason for trade. Comparative advantage is the economic principle that explains why countries produce some goods and services but not others. It is based on the idea that countries are better off specializing in the production of goods and services for which they have a comparative advantage and then trading with other countries for the goods and services they do not produce.2. To exploit economies of scale: This is the second reason for trade. Economies of scale refer to the cost advantages that firms enjoy when they produce on a large scale. When firms produce on a large scale, they can benefit from lower unit costs of production. This occurs because large-scale production leads to lower per-unit costs of production, which arise from factors such as greater efficiency and specialization.3. To access new markets: This is the third reason for trade. When firms trade, they gain access to new markets. This is important because it allows firms to sell their products to a larger number of consumers. It also allows firms to diversify their customer base, which can reduce the risk of business failure.