> Even if there were no legal or immigration costs (which there definitely is), it seems to me they could easily do the same by getting someone from a less prosperous part of the US and moving them to, say, CA. I'm sure this happens all the time.
This logic seems wrong: if a person moves from somewhere to CA, they should now be paid a CA-level salary. Consider that at any point they can quit, and to every other employer they will look like a regular CA job market participant, so the other employers would offer them a CA-level salary. So you can't, in fact, hire someone from outside CA and have them work in CA at a low salary: they would just quickly move to a similar but higher-paid job.
This logic breaks down with visas that restrict your choice of employers. If your freedom to pick your employer is taken away, then your logic is correct: it would be possible to hire someone in CA at a low salary, without them immediately switching jobs, because they are forbidden from doing that.
The 20% premium that the company collects on the salary is (at least partially) a consequence of this lack of employee's freedom in the labour market. Without this restriction you would expect skill-adjusted salaries to be equal for visa and non-visa employees. It's not even anything to do with immigration per se, just this type of visa.
This logic seems wrong: if a person moves from somewhere to CA, they should now be paid a CA-level salary. Consider that at any point they can quit, and to every other employer they will look like a regular CA job market participant, so the other employers would offer them a CA-level salary. So you can't, in fact, hire someone from outside CA and have them work in CA at a low salary: they would just quickly move to a similar but higher-paid job.
This logic breaks down with visas that restrict your choice of employers. If your freedom to pick your employer is taken away, then your logic is correct: it would be possible to hire someone in CA at a low salary, without them immediately switching jobs, because they are forbidden from doing that.
The 20% premium that the company collects on the salary is (at least partially) a consequence of this lack of employee's freedom in the labour market. Without this restriction you would expect skill-adjusted salaries to be equal for visa and non-visa employees. It's not even anything to do with immigration per se, just this type of visa.