[hedgehog]

Housing in Toronto and Vancouver is very expensive, while pay is lower relative to the US. On a purely financial basis it would be hard for many people to move, and then of course there are many other factors. I would guess the bigger impact is how the current situation changes the less visible decisions as academics choose where to apply for positions and how they weight the options they do get. Any researcher facing a significant chance of the grant funding their research getting cut suddenly, or being detained on routine work or family travel, could rationally decide to lean towards a safer and more stable option. Compound that over the next decade and it will have a big effect that reaches far beyond academia.

Edit: Just looking at big tech CEOs, Microsoft, Google, Intel, Nvidia, AMD, all are run by people who came to the US for school.