If you mean parity in wages adjusted for living standards in the country of origin, then it makes more sense. I've never built a factory in a developing nation before, so I could say with certainty how the math works. But finding the right numbers to make everyone "a winner" is probably much harder than you might think.
However, we're still not thinking of something. Why not let the potential workers decide whether or not the lousy job is still better than life on a farm? It's not like they're stupid or something. If they think the lousy is still better than toiling the fields, they would take it. If they don't, then they stay in the fields. What's the problem? What ever they choose, they are still choosing what they think is best for them, even if it is between two lousy choices. If there were no factory, then they'd have one lousy choice.
M