My theory is that this concept mirrors american immigration policy.
In the book 1,000's of flyers sent out over the dust bowl region to get migrant workers to go to california. This was needed to push labor pools up and wages lower
Black lists were made to make plantation interests buddies money to prevent undesirables to work.
In america the ugly truth is if we spent money to have americans pick "your onion crop " food prices would escalate and the osha and regulating commitees would bankrupt most orchards and fields subjecting workers to toxic pesticides without proper protection.
We now have a class of humans living here that can not complain with out fines and deportation can be exploited and see a real connection between the book. and todays reality in the instrumental slavery, of human trafficing in america today.