But isn't the cost of living also higher and you have medical expenses and things? Are you actually taking home double as much, or does a lot of that extra have to go to living expenses that you wouldn't have in Canada?
The cost of living is higher. Medical expenses aren't really a thing for recent grads, and good medical insurance limits your outlay. Normally most people with solid insurance and serious health concerns will max out at a few thousand dollars a year. And for the kinds of jobs we are talking about, that isn't a big deal.
Anyways, I'm making way beyond 2x as much as I ever could have in Canada. Also I get to work on world class tech, with world class people. And when I changes jobs, I don't have to take major compromises. There are way more high quality employers in the bay area than anywhere else for technology!
I do take home a lot more than I would in the Canada. Cost of living in the US isn't 2x Canada but salaries for tech jobs are (And keep in mind that was a while back, it's now more than that). Health is covered by my employer, I pay nothing directly for it. (Definitively not the majority of cases, most people have some amount of contributions to it). But if I had stayed in Quebec I'd have been in the top bracket and paying a huge chunk in taxes. Even as I live in a state with high social programs (MA).
So to conclude, if you are in a field like tech, medicine, finance you will be significantly better off in the US than Canada. Other fields with similar income levels between Canada and the US I'd say Canada will offer a better standard of living.