What Is Ultimatum Game Theory?


Martha Robinson

Ultimatum Game Theory: Understanding the Psychology Behind Fairness in Transactions

Have you ever been offered a deal that seemed unfair to you? Maybe you were offered a low salary or a low price for something you were trying to sell.

How did you react to this offer? Did you accept it, negotiate, or reject it altogether?

These types of scenarios are studied through Ultimatum Game Theory, a branch of game theory that focuses on decision-making in transactions involving two parties. In this article, we’ll dive into what Ultimatum Game Theory is, how it works, and why it’s important.

What is Ultimatum Game Theory?

Ultimatum Game Theory is an economic experiment that involves two players: the proposer and responder. The proposer is given a sum of money and must offer a portion of it to the responder.

The responder can either accept or reject the offer. If they accept, both players receive their respective amounts. If they reject, neither player receives any money.

The catch is that the responder knows the amount of money being split and has the power to reject any offer they deem unfair. This creates an interesting dynamic between the two players as both must weigh their own self-interest against what they perceive as fair.

How does Ultimatum Game Theory work?

To better understand how Ultimatum Game Theory works, let’s look at an example:

Player A is given $10 to split with Player B. Player A offers Player B $3, leaving $7 for themselves.

Player B rejects this offer as they feel it’s unfair to only receive 30% of the total sum. Neither player receives any money.

In this scenario, Player A may have acted rationally in offering only $3 as it would leave them with more money overall. However, Player B’s rejection shows that fairness plays an important role in decision-making for both parties.

Why is Ultimatum Game Theory important?

Ultimatum Game Theory provides insight into human decision-making and the psychology behind fairness in transactions. The results of these experiments have shown that people are willing to reject unfair offers even if it means receiving nothing at all. This suggests that people value fairness and are willing to forego their own self-interest in order to maintain it.

Additionally, Ultimatum Game Theory has real-world applications in areas such as negotiations, salary discussions, and political decision-making. By understanding the role of fairness in these situations, individuals can make more informed decisions and negotiate better outcomes.


Ultimatum Game Theory is a fascinating branch of game theory that sheds light on how people make decisions in transactions. Through this experiment, we see that fairness plays a crucial role in decision-making and that people are willing to reject unfair offers even if it means receiving nothing at all. Understanding Ultimatum Game Theory can provide valuable insights into negotiations, salary discussions, and other real-world scenarios where fairness is important.