No help with evidence here, but a thought:

This sort of argument is generally made in favor of globalization and other such economic arrangements. However, is it actually a real dichotomy? In the context of an extremely globalized world in which developed nations have the economic clout to extract labor at ridiculously low prices, closing any individual sweatshop-factory is on the margin going to push people into worse poverty. That sort of economic system is not the only option, however, and actions to end that system potentially produce outcomes better than 'prostitute' or 'sweatshop worker'.