[User23]

You can’t really refute the claim that H-1B drives down the market price of labor by citing their price in the market. You have to show those wages would be the same even without the immigrant workers. From a basic supply and demand perspective that sounds unlikely, but markets are complex dynamic creatures so perhaps it’s the case. Nevertheless it needs to be shown.

[UncleMeat]

Similarly, it is very challenging to demonstrate this claim. It does not seem like the sort of thing we should take as a given.

[User23]

Agreed, markets are complex. And frankly I don't find market based arguments for or against immigration particularly compelling for that reason. So far as I can tell we really have no reason to believe either side's claims along that dimension.