Here the world price of phones, P_W, is below the autarky price, P_A. When the economy is opened to international trade, imports enter the domestic market, and the domestic price falls from the autarky price, P_A, to the world price, P_W. As the price falls, the domestic quantity demanded rises from Q_A to Q_D and the domestic quantity supplied falls from Q_A to Q_S. The difference between domestic quantity demanded and domestic quantity supplied at P_W, the quantity Q_D − Q_S, is filled by imports.