Yeah, the argument is superficially plausible. Essentially, the wage earner is so desperate that they have literally zero bargaining power.

The part that's missing is that greedy capitalists will bid productive workers away from each other until those workers are actually making a wage roughly commensurate with their productivity.  

Undisciplined

econ

There Is No Such Thing as "Wage Slavery"

 i dont believe any one can be a slave if there is the possibility that they can work hard enough 
   
The situation of wage slavery can be loosely defined as a person's dependence on wages (or a salary) for their livelihood, especially when wages are low, treatment and conditions are poor, and there are few chances of upward mobility.
