Without free trade, domestic companies may have enjoyed monopolies or oligopolies that enabled them to keep prices well above marginal costs.

ECONOMIST: A short tour of economic theory

Small economies need trade to specialise, but the pressure of selling into a big domestic market helps companies in large economies remain competitive even without a lot of competition from imports.

ECONOMIST: BRICs, emerging markets and the world economy

When competition is restricted due to trade barriers, the only winners are the protected companies who make up the domestic industry.

FORBES: Free Trade Is The Fix For Rising Health Insurance Premiums

Actrade International, New York City, helps companies export products via an overseas network of distributors, and buys domestic commercial trade acceptance drafts at a discount.

FORBES: The Hot Ones