Mark - since we've established that 3rd world labor is inherently exploited, what would you propose as the alternative? A minimum wage that removes the profit motive of creating third-world factories? So instead of working 12 hours for, say, $2/day, they're working 0 hours for $0/day. Not to mention the happy side-effect of removing what little developmental steps they've taken.
I can read this comment in one of two ways. One is, "Evil will be done. Shouldn't we do the least amount of it?" The other is, "Evil will be done. Shouldn't we recommend the least amount of it is done?"
The first way is a version of doing evil that good may result. We are the ones doing evil, or at least cooperating with evil in a morally culpable way. The only answer to this question -- and I don't mean the ideal Catholic answer, or the traditional Christian answer, I mean the only rational answer -- is, "No, we shouldn't do any evil whatsoever."
If the answer were, "Yes, we should do evil to someone if it betters his standard of living," then why not enslave destitute foreigners? The money paid for them would help their families, and they themselves would be materially better off sleeping in the basements of suburban American houses and eating day-old suburban American bread than living in their own countries.
The second way of reading the comment seems to be a version of counseling the lesser of two evils, which holds that, when someone else is morally certain to do some evil, we may counsel him to do a lesser evil instead. (I recently read that not all Catholic moralists believe counseling the lesser of two evils is morally acceptable, but that's a discussion for another time.)
What are the two evils we are to counsel others -- specifically, an American corporation -- regarding?
One evil, clearly, is exploiting Third World laborers. Stephen seems to be suggesting the other evil is not opening a just factory in the Third World. But "not opening a just factory in the Third World" is not an evil act for an American corporation. We can't tell a corporation, "You should choose to exploit these workers in this foreign city rather than allow them to starve," because the corporation isn't allowing them to starve if it doesn't open a factory there. A given corporation has no specific moral duty toward the poor of some arbitrarily-chosen city. It shares -- or rather, its stockholders and directors share -- a moral duty toward the poor of the whole world, but that does not imply a moral failure if it doesn't open a factory in a particular Third World location.
Still, if we grant that recommending factories exploit laborers is counseling the lesser of two evils (whatever the other evil might be), we need to consider our own culpability. Most of us aren't formally culpable; we aren't making (or failing to make) decisions that directly cause exploitation. We may not even be immediately cooperating with the exploitation. But our moral distance from exploitation -- especially for rich Americans who read all sorts of stuff on the Internet -- isn't necessarily great enough for us to reasonably argue we're counseling others to do the lesser evil.
I suppose my wrap-up is to deny that Third World laborers are "inherently exploited." If indeed they are exploited, they are exploited by other humans. If those other humans are us, we need to stop it. If they aren't us, we need to counsel the exploiters to stop it, or at least to limit their exploitation, without inventiong moral burdens they do not actually bear.