No they don't. According to Amnesty International there's about 40million slaves in the world, which sounds like a lot until you realize that's only about 1% of the world's workforce. The reason they are slaves is not to make things cheaper forthe rest of us but because they live in corrupt societies that allow it. The amount of slaves in a country is highly correlated with that country's placement on the WBO's global corruption index.
The WBO's global corruption index surely fails to take into account inter-national corruption. That corrupt resource extraction requires people outside the country interested in purchasing the outputs.