When a country experiences economic growth, its export increases, leading to a lower export price. Bhagwati regarded the lower price as immiserizing. He also needed a higher import price to complete his theory, but his lower import demand should lead, contradictorily, to a lower import price. This book works out the larger import demand from economic growth to satisfy Bhagwati's wish for a higher import price. In addition, it also proves that this increase of export and import is not immiserizing, but blessing. Production efficiency and technology are the two causes of economic growth. When the trading partner also benefits, it has no reason to complain.