It's a simple number of relative poverty. Do you happen to know what percentage of the population is in this so-called slave work? Proof?
I'd be interested in any metric you come up with, provided it's based on fact and logic.

"The liberals can understand everything but people who don't understand them."
Lenny Bruce

"The cleverest of all, in my opinion, is the man who calls himself a fool at least once a month."
Dostoevsky