Economic theory indicates that trade occurs because it is mutually enriching. It has a positive economic effect like that caused by technological change, whereby economic efficiency is increased, allowing greater output from the same amount of scarce productive resources. By allowing each participant to specialise in producing what it is relatively more efficient at and trading for what it is relatively less efficient at, trade can increase economic well-being above what would be possible without trade. This book discusses current key concepts, policies, forecasts, and international trends in the U.S. trade sector.