Although the basic arguments of trade were established more than two centuries ago, they continue to be debated. Protectionism is in the news again as nations struggle with rapidly mounting job losses and plunging industrial production. Almost without exception political leaders and their top-level economic advisers across the globe have publicly endorsed “free trade” principles and warned of the risks to all economies if countries raise trade barriers and cause international trade to fall faster than it would from the effects of declining demand alone. In particular, they have emphasized that such actions would be especially dangerous in the current setting...