Courtesy of The Economist. A growing number of American companies are moving their manufacturing back to the United States IN 2005, A START-UP company from California called ET Water Systems decided to move its manufacturing operations to China. At the time there was a general exodus to Asia in search of lower costs, recalls Mark Coopersmith, the firm’s chief executive. ET Water Systems, which builds sophisticated irrigation devices for businesses, quickly started losing money, not least because it had so much capital tied up in big shipments of goods which took weeks to cross the oceans. Innovation suffered from the…