Outsourcing to other countries has become a hot political issue in America. Contrary to what John Edwards, John Kerry and George Bush seem to think, it actually sustains American jobs.

Earlier this month, President George Bush’s chief economic adviser, Gregory Mankiw, once Harvard’s youngest tenured professor, attracted a storm of abuse. He told Congress that if a thing or a service could be produced more cheaply abroad, then Americans were better off importing it than producing it at home. As an example, Mr Mankiw uses the case of radiologists in India analysing the X-rays, sent via the internet, of American patients.

Mr Mankiw’s proposition, in essence, is the law of comparative advantage, first postulated by David Ricardo two centuries ago and demonstrated to astonishing effect since. Yet the Republican speaker of the House of Representatives, Dennis Hastert, joined Democrats in their rebuke of Mr Mankiw for approving of jobs going overseas; another Republican called for his resignation. The White House gave Mr Mankiw only lukewarm support—unsurprisingly, since Mr Bush recently signed a bill forbidding the outsourcing of federal contracts overseas. And the Democratic presidential contenders? Mr Mankiw had just written their attack ads.

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