It is an economic theory made in response to SET criticism.
As long as there is a perceived sense of fairness in the relationship
It criticises social exchange theory for ignoring the crucial role of equity.
Equity means fairness
Walsteret al (1978) suggested that what matters most with equity is that both partners' level of profit (their rewards minus the costs) is roughly the same.
When one partner over-benefits and the other under-benefits this is when there is a lack of equity and dissatisfaction/unhappiness will occur.
Examples of inequity
Under-benefit: likely to feel the most dissatisfied - they may show anger, hostility, resentment and humiliation.
Over-benefit: they will feel guilt, discomfort and shame.
Satisfaction in a relationship is about perceived fairness.
What does equity theory suggest?
That the size or amount of rewards and costs do not matter, instead it is the ratio of the two to each other.
Satisfying relationships are marked by negotiations to ensure equity between partners - this therefore suggests relationships involve making trade-offs.
Consequences of inequity
Problems arise when one partner puts a great deal into the relationship but gets little from it.
A partner who experiences inequity will become distressed and dissatisfied with the relationship.
The greater the perceived inequity, the greater the dissatisfaction: example of a correlational relationship and applies to over-benefitted and under-benefitted partners.
Consequences of inequity types
Changes in perceived equity - what makes us most dissatisfied is a change in the level of equity as time goes on.
Dealing with inequity - the partner dealing with inequity will work hard to make the relationship more equitable as long as they believe this is possible and the relationship is salvageable. The more unfair the relationship feels, the harder they will work to restore equity (correlation). Or, the partner will revise their perception of rewards and costs so that the relationship feels more equitable if nothing actually changes.