I think this is true when we're talking about a large number of immigrants in general, where a significant percentage of them don't have advanced skills (akin to any large sample-size of humans). The dynamic changes entirely when the sample size is comprised mostly of immigrants with advanced skills.
If we allowed in 100,000 immigrant astronauts, I think it's safe to say they'd impact the hiring prospects of American astronauts. And they wouldn't consume enough goods and services to spawn new space ventures that create 100,000 new astronaut jobs.
If we allowed in 100,000 immigrant astronauts, I think it's safe to say they'd impact the hiring prospects of American astronauts. And they wouldn't consume enough goods and services to spawn new space ventures that create 100,000 new astronaut jobs.