What Is Public Goods Game Theory?


Diego Sanchez

Public goods game theory is a concept that has been widely studied in economics, political science, and sociology. It is a model that seeks to explain how people decide to contribute to public goods, which are resources that are shared by everyone in a community or society.

What are Public Goods?

Public goods are resources that are non-excludable and non-rivalrous. Non-excludable means that it is impossible to prevent anyone from using the resource, while non-rivalrous means that one person’s use of the resource does not diminish its availability to others.

Examples of public goods include clean air, national defense, and street lighting. It is important to note that public goods can also be man-made products like software or scientific research.

How does Public Goods Game Theory work?

Public goods game theory assumes that people act rationally and make decisions based on self-interest. In this scenario, individuals must decide whether to contribute their own resources towards the creation of a public good or keep them for personal use.

The key element of the game theory is that everyone benefits from the creation of a public good, regardless of whether they contributed to it or not. This creates an incentive for individuals to free-ride on the contributions of others and not contribute themselves.

To counteract this incentive for free-riding, game theorists suggest various mechanisms such as taxes or incentives for contribution. These mechanisms aim to increase the likelihood of individuals contributing towards the creation of public goods.

The Tragedy of Commons

Public goods game theory also addresses the tragedy of commons problem. This problem arises when individuals overuse or exploit a common resource because they do not bear any cost for their actions.

The classic example is overfishing in oceans where individual fishermen continue fishing until the fish population collapses even though it would have been better if they had stopped earlier.

To avoid tragedies like these, game theorists suggest implementing regulations, taxes, or other mechanisms that create a cost for overusing or exploiting public goods.


Public goods game theory is an essential tool for understanding how individuals make decisions regarding the creation of public goods. It provides insights into the incentives and motivations that drive people’s behavior in such scenarios.

The theory also highlights the importance of implementing mechanisms that encourage individuals to contribute towards public goods and prevent overuse or exploitation of common resources.

In summary, understanding public goods game theory is crucial in developing policies that promote social welfare and sustainable development.