Actually, sending jobs overseas IS pure economic theory, because the employer is seeing a way to reduce his costs. If he can save $5 on every widget he produces while his competitors don't to pay American workers, who's going to be able to undercut the competition's prices and corner the market? IOW, if you want jobs to stay in the country, you're going to have to make it illegal to outsource, and that is pure protectionism. Prices for everything would go sky high.When jobs are being sent overseas because a manufacturer does not want to pay the prevailing wages here, all economic "theories" go out the window.
A declining manufacturer base with an increased population combined with massive pumping of the markets does not work.