I'm sorry, not only is this far from definitive, it's not even a sign of an 'early' exodus.

There is not really any exodus, sadly. The US still is significantly more competitive and offers much higher upsides to talented people willing to take risks. I live in the EU and want us to succeed, but I'm skeptical about our ability to compete with America economically and technologically, because we foster a different type of spirit.

It would be nice if this didn't matter.