FREEDOM TO FAIL:

From 80 to 90 percent of all start-ups fail, "but that's O.K.," said Eze Vidra, the head of Google for Entrepreneurs Europe and of Campus London, a free work space in the city's booming technology hub. In Britain and the United States, "it's not considered bad if you have failed," Mr. Vidra said. "You learn from failure in order to maximize success."

That is the kind of thinking that drew Mr. Santacruz to London. "Things are different in France," he said. "There is a fear of failure. If you fail, it's like the ultimate shame. In London, there's this can-do attitude, and a sense that anything's possible. If you make an error, you can get up again."

Mr. Santacruz had a hard time explaining to his parents his decision to leave France. "They think I'm crazy, maybe sick, taking all those risks," he said. "But I don't want to wait until I'm 60 to live my life."

France has been losing talented citizens to other countries for decades, but the current exodus of entrepreneurs and young people is happening at a moment when France can ill afford it. The nation has had low-to-stagnant economic growth for the last five years and a generally climbing unemployment rate -- now about 11 percent -- and analysts warn that it risks sliding into economic sclerosis.

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