Zero-sum game

Definition

A zero-sum game is a situation in game theory and economics where one participant’s gain or loss is exactly balanced by the losses or gains of other participants.

What is zero-sum game?

Zero-sum games are typically characterised by competition, where one participant’s success directly comes at the expense of another participant’s failure.

In a zero-sum game, the total value or wealth in the system remains the same before and after the interactions among participants. This means that any gain by one participant is matched by an equivalent loss by another. Contrastingly, in non-zero-sum games, it is possible for all participants to gain or lose collectively. Cooperative activities, trade, and negotiations often fall into this category.

In economics, the concept of a zero-sum game is used to analyse situations where resources are distributed or redistributed among participants. It is important in understanding issues like wealth distribution, taxation, and economic policies.

While some situations can be modelled as zero-sum games, in reality, many interactions are more complex and can involve elements of cooperation, mutual benefit, and positive-sum outcomes.

It’s important to note that not all real-world situations can be accurately described as zero-sum games. Many economic and social interactions involve complex dynamics where outcomes are not strictly tied to winners and losers. Understanding whether a situation is zero-sum or not is crucial in making informed decisions, especially in competitive environments.

Example of zero-sum game

Imagine two friends, Alice and Bob, playing a simple card game where they bet $10 on each round. In this game, the total amount of money at stake remains constant – if one player wins $10, the other player loses $10, resulting in a net change of $0.

For instance, if Alice wins a round, she gains $10, and Bob loses $10. The overall change in wealth between Alice and Bob is zero. Similarly, if Bob wins a round, he gains $10, and Alice loses $10, resulting in a net change of $0.

In this card game, the total amount of money in the system stays the same, and any gains made by one player are offset by losses experienced by the other player.