The Republicans' immigration ... conundrum? James Surowiecki in the new New Yorker:

In one famous study, the social scientist AnnaLee Saxenian showed that Chinese and Indian immigrants alone founded a quarter of Silicon Valley start-ups between 1980 and 1998, while a 2007 study found that a quarter of all technology and engineering start-ups between 1995 and 2005 were founded by immigrants. On a larger scale, more than forty per cent of the companies in the 2010 Fortune 500 were started by immigrants or their children.

He writes: Tough times have always lent themselves to nativist sentiments and closed-door policies. But in the case of highly skilled immigrants these policies are a recipe for stagnation.