When a country that has historically been a main exporter/producer of a certain good remains the producer of that good even if a different country could do it for cheaper. Example: Assume china is the main producer of buttons in the market, and has a big button industry. They produce for the whole world. This would lead to other countries, lets say Vietnam, to be blocked out of the button industry, because when entering the market their prices are higher due to a lack of economies of scale. This results in other countries being trapped out of the button industry unless their initial cost of production is lower then China’s current cost of production.