Equity

"Equity theory is a general model of how people decide whether an exchange is fair and what they do if they determine it is not....A well-run company, for example, should have an equitable balance; the employer gives the employee a living wage in exchange for the employee's time and effort. If, however, management tries to increase productivity without a corresponding increase in payment, then the employees may feel that they are being treated inequitably and start compensating themselves informally by staging work slowdowns or stealing company property....
Restoring equity can be tricky, but the rewards are well-worth it. Money, of course, is the ultimate equalizer. If you want your employees to work harder, then you pay them more. Sometimes, though, money is not the answer. The budget may not allow it, or the situation may be such that no amount of money would be sufficient (e.g., the boss is abusive). Believe it or not, outstanding results have been achieved simply by treating employees like human beings."
Research done in 1990 on aerospace and automotive manufacturing workers shows how a little compassion can make a big difference."

This is what Charles said.