As a Canadian who will be going to work in the US through a TN Visa. I wonder if Canadian hires are also seen as a "cheaper" alternative to hiring locally.
The barrier to getting another TN for Canadians for another employer is too low to allow for these kind of shenanigans. Having to move back to Canada isn't that horrible either, and they don't get the foreigner isolation effect that ESL people have.
the class of status (TN) is less important than the mindset of your new employer.
No visa class requires you to be paid under market (some even require that you are paid a wage comparable to an american)
If an employer is trying to "maximize profits" through non-american workers, they will do it regardless of what status you hold.
If an employer is simply trying to find the somebody to "do the job" regardless of status or citizenship then it is unlikely you will experience any difference in treatment.
On a personal note, I had been on a TN for 2.5 years and was paid at (or slightly above) market rate for the entirety of the time.
At no time did my employer seek to use my TN as a way of leveraging down my pay.
We hired quite a few americans as well (half a dozen or so, it was a small company).
If we could have found more qualified candidates, we probably would have hired more
(american or not, we scoured github for candidates as this tended to provide the best candidates. since github user profiles generally do not provide citizenship information, we had to be open to hiring local or possibly non local if we found somebody who looked promising).
I worked in the US on an E3 Visa, which is pretty much like a H1B that is only available to Australians.
As I understand it, both of those require you to be paid at least the 'prevailing wage', and before the job is offered to you:
"This Form ETA-9035 needs to be posted in “two conspicuous locations” at the work site for 10 consecutive days where the H-1B (or H-1B1, or E-3) nonimmigrant will be employed. You must post the entire LCA, including the instructions and the portion containing information on the prevailing and offered wages."
ie, your employer has to post the fact that they're going to employ someone at a certain wage within the office.
That leads to fun times when your visa is up for renewal and the company is obliged to tell everyone what your wage is.
In my case I believe I was being paid more than some of my roughly-equivalent colleagues and there was some concern that the posting might ruffle some feathers. When I decided i'd had enough of the US and that it was time to move on I was told to pick anywhere in the world and my employer would pay to move me there and set me up so I could keep working for them. I was the complete opposite of an exploited foreign worker.
I was in the US working on a TN for 1.5 years. At that time, TN's were not tied to the employer. I'm not sure if this is still the case. You just had to have a job in the field that you came in on. That said, you couldn't apply for a greencard while on a TN. For that you needed to get an H1B.
For our company I was paid the market rate, no different than a local hire.
