India may be a big draw, but the U.S. faces competition for talent elsewhere. Canada and Australia have recently changed their policies to favor immigrants with university degrees and business expertise. The U.S. continues to favor relatives over skilled workers.

Meanwhile, programs sponsored by Singapore, Israel, and Ireland are luring entrepreneurial expatriates back from the U.S. One of the pioneering initiatives is in Taiwan. A technology incubator called the Hsinchu Science Park focuses on recruiting Taiwanese-born U.S. residents to come back home. One-third of the park's 370 companies are run by returning Taiwanese; among them is a Stanford alumnus who launched Macronix International, a semiconductor business that now has a market cap of $1.3 billion. Says David Heenan, who writes about these programs in his new book Flight Capital: The Alarming Exodus of America's Best and Brightest: "On a 10-point scale, in terms of national incentives, we're at about a one."