Employers pay their employees exactly what they're worth - by definition.
If an employee is dissatisfied with their pay, they have the option to either negotiate a higher salary or find another job with higher pay.
If an employee is dissatisfied with their pay, they have the option to either negotiate a higher salary or find another job with higher pay.
As an approximation, employees are paid what they're worth. It's an approximation, not definitional.
Being more specific - there may be transition periods where you may become more valuable (through training or whatever) at which point you have the opportunity to seek higher compensation. If one does not seek higher compensation, then one is trading their higher potential salary for other wants/needs (maybe they trade the enjoyment of their current work at a lower pay over the higher salary at another job).
In equilibrium and in an efficient market, the value of the labor provided is equal to the cost of the labor provided.
Of course, in the real world, there are inefficiencies and irrational behaviors, but to a first order - it's approximately correct.
(/s)
There are issues when we take the "Market is always right" approach to defining our morals btw. I prefer if our morals came from another power.
That makes no sense to me. When I hire someone, it's in the expectation that the extra money they bring in is more than what they're being paid. They're worth what they bring in, and because I want to make a profit, I pay them a bit less than that.