[likpok]

> most of the best upper year engineers finish their studies and then abandon Canada for SV.

That might have something to do with it. If none of the good people are willing to stay for reasonable rates, companies may have trouble finding people regardless. That can reduce the costs of moving to SV.

For example: if the people you'd want to hire are comparing your offer against a SV salary, you may need to pay SV salaries anyway. But you'll still lose out on people who also like the job density of SV, or the weather, or that their friends have moved.