The home market effect is an economic phenomenon that explains why goods with high economies of scale and higher transport costs tend to be produced in countries with large domestic markets. It is a key concept of the New Trade Theory that challenges the classic theory of economics which states that countries have comparative advantage and specialize in production depending on such factors as labor or natural resources.

Studies have shown that the home market effect is due to the same economic forces that underlie modern competitive markets. Primary among these forces are economies of scale from producing goods in large quantities and transaction costs associated with the transport and exchange of goods across borders. In countries with large domestic markets, these forces combined with increasing returns to scale tend to outweigh any potential gains in productivity or cost reduction that could be achieved through specialization. As such, goods which have large fixed costs of production and significant costs of transport to other countries tend to be produced in and exported by countries with large domestic demands.

For investors and businesses, understanding the home market effect can be a significant advantage in making international business decisions. Companies should think carefully not only about production costs but also the costs associated with transporting goods when considering entering new markets. Similarly, businesses can benefit from investing in the production of goods and services in countries with large domestic markets, as the potential for market size and higher returns from the home market can outweigh any potential cost savings of specializing production.

The home market effect has now been a part of the global economic landscape for decades, and its influence on international business is only increasing. As the costs of transporting these goods steadily decreases and countries increasingly turn to global markets to maximize efficiency, the home market effect will become even more essential in making strategic production decisions. As such, understanding this concept is becoming more important for businesses and investors considering their international market entrance and expansion.