“The best slave is someone you overpay and who knows it, terrified of loosing his status.”
Employment is not slavery. Yet, many of the attributes an employee exhibits while in employment, and the expectation that the employer has over the employee, resemble employment to slavery in many aspects.
Skin in the game is a fascinating book by Nassim Nicholas Taleb (famous author of The Black Swan, Fooled by Randomness, etc.). The text presented as a collection of many essays (as it seemed to me) explaining many aspects of ancient to modern life, with one central theme, hidden asymmetries of daily life. While explaining the asymmetries and their impacts, the writer draws a parallel between slavery to the employment situation.