That's not how the real world works, though. People (usually) get paid the minimum they'll accept, as long as that value is less than or equal to what they're worth.
If a Polish developer has a choice between working for a company in his own country for $x, or for a foreign company for $2x, he'll take the second offer, even if that same company is paying American developers $8x.
If you were right, then someone else will realize there's cheap/good labor available, and poach him at $3x. Then, someone else will steal him at $4x. And so on, until he's making close to what the American dev makes.
Tech hiring is extremely competitive. If there were easy-access to a large, skilled labor force for one quarter the money of the currently available labor market, don't you think tech firms would jump on the opportunity for cheap labor? I know when I was hiring I would have.
Sure, to some extent. However you have to remember the following points:
- Not all employers want remotely based staff
- If the wages are significantly better than local jobs, the developers may compete with each other by offering lower wages
- It may be harder to find remote staff than local staff
- While it's easy to say "pay him more and he'll move to us", it's worth remembering that workers in any industry don't always chose jobs based on salary alone.
- If companies continue raising salaries to poach staff, what happens when the cost becomes equal to that of local workers? They chose local workers. So while the salary may not be as low as it might be, it won't reach the same levels as local staff.
If a Polish developer has a choice between working for a company in his own country for $x, or for a foreign company for $2x, he'll take the second offer, even if that same company is paying American developers $8x.