What attracts Swiss scientists to the United States? The issue has shot to prominence since Novartis announced it would run its research from Massachusetts.
Christian Simm, who heads the Swiss Science and Technology office in San Francisco, has studied the phenomenon.
"I prefer to call it brain circulation," he told swissinfo. "Until I'm dead or retire, no one can say I've been drained to the US."
Simm, who has a doctorate in engineering physics from the federal institute of technology in Lausanne, runs the 2,300-member web directory, Swiss Talents, a network of highly skilled professionals living abroad who are Swiss or have strong ties to Switzerland.
"We don't have an exact figure," he said. "But there may be up to 5,000 Swiss scientists and engineers in the US out of the total 500,000 Swiss living outside of Switzerland."
One of those is Daniel Kaufmann, a specialist in infectious diseases, who was born in Lausanne and studied there and in Zurich. He came out to Boston six months ago, funded by a Swiss grant and has had an opportunity to observe the differences between the countries.
Kaufmann told swissinfo he could understand perfectly why Novartis had decided to move its operations.
"The Boston area is an outstanding place to be a researcher and even in the US, it is an outstanding place compared to other cities and academic centres.
"Of course, there are very good research centres in Switzerland but what is unique here is the amazing concentration of world-class people in the same area, and the rapidly expanding breadth of knowledge in the life sciences, computer sciences, micro and nanotechnologies.
"The team work is amazing. If you don't know a technique, you can always find someone next door who can help you out."
Kaufmann said there was a particularly strong link in the Boston area between industry and the academic world. "It's important because both can benefit. And I'm sure it influenced Novartis to have a close relationship with the academic world."
Scientists in the US also benefit from a more liberal university tenure track system, which means more opportunities said Simm. "The size of Switzerland means that if you don't get the job you want, it might not be available at another university so you are forced to emigrate."
Simm pointed out that phenomena like Silicon Valley and the preponderance of biomedical research in the Boston area were hard to replicate. "There are 3.5 million people in Silicon Valley. That's half the entire population of Switzerland."
Both observers were struck by the difference between the Swiss and American attitudes to risk taking.
"In Europe, people are very constrained before giving you the means to reach your goals," said Kaufmann. "Here they trust the innovative capacity of young people more. The speed with which a hypothesis becomes research is amazing."
Simm said he was unconcerned by the numbers of Swiss scientists working in the US. He preferred, he said, that they maintained close contact with Switzerland and benefited from their international experience before rushing home. He added that for him it was a source of pride that their skills are so eagerly sought.
by Vincent Landon, Boston