Equity theory
Equity theory is a theory that attempts to explain relational satisfaction in terms of perceptions of fair/unfair distributions of resources within interpersonal relationships. Considered one of the justice theories, equity theory was first developed in 1963 by John Stacey Adams. Employees seek to maintain equity between the inputs that they bring to a job and the outcomes that they receive from it against the perceived inputs and outcomes of others. Equity theory proposes that individuals who perceive themselves as either under-rewarded or over-rewarded will experience distress, and that this distress leads to efforts to restore equity within the relationship. It focuses on determining whether the distribution of resources is fair to both relational partners. Equity is measured by comparing the ratios of contributions and benefits of each person within the relationship.
Case of US
Cowherd and Levine (1992) used a sample 102 business units in 41 corporations to examine whether the size of the pay differential between lower-level employees and top management had any impact on product quality. Cowherd and Levine suggest that individuals often compare their pay to that of people higher in the organization structure. If lower-level employees feel inequitably treated, they may seek to reduce their effort to achieve equity. Quality, in their study, was defined as customer perceptions of the quality of goods and services. They hypothesized that extra role, or citizenship behaviors, such as freely offering to help others, following the spirit rather than letter of rules, and correcting errors that would ordinarily escape notice, would be less likely when pay differentials between hourly and top managerial employees were large. Their results supported this hypothesis, suggesting that organizations need to take care that they not forget the potential adverse motivational consequences of executive pay for the motivation of other employees.