Equity Theory, proposed by John Stacey Adams, is a motivation theory that emphasizes fairness in the workplace and its impact on employee motivation and behaviour.

Input–Output Ratio
Inputs
These are what employees contribute to their jobs, such as:
Outputs
These are the rewards employees receive, including:
Employees evaluate their own input–output ratio and compare it with that of others.
Inequity in the Workplace
Two common types of inequity include:
Impact on Motivation
When an employee is dissatisfied with their input–output ratio compared to peers, motivation can be at risk.
Similarly, when employees perceive their reward-to-effort ratio as higher than others, it may create feelings of guilt and negatively affect motivation, as individuals naturally strive to maintain balance and fairness.