Exploitation in Transactions

I would want to look at more than just the working conditions and the wages to establish whether they've been exploited. So somebody making a very expensive piece of computer equipment in terrible conditions paid a twenty wage for that would be a classic case of somebody being exploited. Here in the middle is what I would call a fair exchange. In fair exchange there are goods and services traveling in both directions. Somewhere between a fair exchange and a gift is something that I call a benefit. If we consider the counterpart to a benefit something that lies on this spectrum between the fair exchange in the middle and theft or robbery at the end that's what I think exploitation is.