The background in my book is based in the future, and society has high advance technology, and in knowledge but their govt enslaves majority of the people. Enslaving people regardless of race is acceptable in society mainly because people lost their values of humanity. Once you're a slave their masters can do anything to you. Trying to figure out how can enslaving people be economically feasible, and acceptable mainstream. People who end up becoming slaves are criminals, rebels, Soldiers went A-wall, born a slave from a slaved mother, kidnapped, homeless/drug addicts or even disabled, captured POW. Basically the cess-pool of society are enslaved. Only way I can think of making it work is a hybrid of corporation/Communism/govt type of economic system. At the same time enslaving people conflicts with a couple of things with people who are employed, and buying masses of product. The less people shop, and there is less jobs unless I maybe incorporate where slaves can buy certain products for themselves. I also have the slave market is a huge business as well. So why would wealthy business owners employ people instead of buying slaves? Best thing I can think of is there too much regulations(red tape), taxes, fee's, maintenance cost(feeding, sheltering) that involve buying a single slave. Plus a single slave even though faces death defying obedience of their masters still can pose a risk of trouble, or even getting killed by one.