Anecdote time: I worked in thailand for a while on a ship. Our captain lived there permanently. He told us stories about how the construction workers in his area were all cambodian because as you said: Cheaper and less likely to complain about conditions.
I have no doubt that the cities on the southern chinese border have a certain amount of foreign workers there for even worse than the usual shitty day laborer wage.
Anecdote time: I worked in thailand for a while on a ship. Our captain lived there permanently. He told us stories about how the construction workers in his area were all cambodian because as you said: Cheaper and less likely to complain about conditions.
I have no doubt that the cities on the southern chinese border have a certain amount of foreign workers there for even worse than the usual shitty day laborer wage.