Here the world price of auto seats, PW, is below the autarky price, PA. When the economy is opened to international trade, imports enter the domestic market, and the domestic price falls from the autarky price, PA, to the world price, PW. As the price falls, the domestic quantity demanded rises from QA to QD and the domestic quantity supplied falls from QA to QS. The difference between domestic quantity demanded and domestic quantity supplied at PW, the quantity QD − QS, is filled by imports.