chapotraphouse

It is a safe assumption that a majority of current US scientists who leave will most likely go to Europe, yes. But long term that's a relatively small piece of the brain drain issue compared to which countries will end up producing more (and better-educated) scientists in the coming years. It's not just a matter of the ones that already exist going elsewhere, it's that there is so much less incentive and ability for a person to become a scientist in the US than there used to be while there is significant incentive and ability to become a scientist in China. I expect the incentive in the EU is also going to rapidly deteriorate, so the influx of US scientists there is just a postponement of brain drain in the west as a whole.