Social norms are unwritten rules that govern behavior in a society. They are not formal laws that are enforced by the government, but they are generally followed by members of the society because they are seen as being important for maintaining social order and cooperation.

Social norms can influence the decisions that people make in experiments, such as how much they are willing to pay for a good or how much they are willing to cooperate with others. They can also affect the results of experiments, such as the level of cooperation or the efficiency of a market.

The ultimatum game is a game in which two players are given a sum of money and must decide how to divide it between them. One player, the proposer, makes an offer to the other player, the responder. The responder can either accept the offer or reject it. If the responder accepts the offer, the money is divided according to the terms of the offer. If the responder rejects the offer, neither player receives any money.

The Nash equilibrium in the ultimatum game is (1, 99). This means that the proposer offers the responder $1 and the responder accepts the offer. This is the only outcome that is stable, meaning that neither player has an incentive to deviate from it.

Social norms can lead to higher offers from the proposer and more acceptances of offers by the responder. This is because social norms can make people feel obligated to behave in a fair and cooperative manner.

The public goods game is a game in which players contribute to a common pool of resources. The amount that each player contributes is private information. The total amount of resources in the pool is then multiplied by a factor and distributed equally among all players. This means that each player benefits from the contributions of all other players, regardless of how much they contributed themselves.

The Nash equilibrium in the public goods game is for each player to contribute nothing. This is because each player has an incentive to free-ride on the contributions of other players. This means that they can benefit from the public good without having to pay for it.

Social norms can lead to higher contributions from players and more efficient outcomes. This is because social norms can make people feel obligated to contribute to the public good, even if they do not directly benefit from it.

The tragedy of the commons is a situation in which a common resource is overused and depleted. This can happen when each individual has an incentive to use the resource as much as possible, even if it means that the resource will be depleted in the future.

Social norms can lead to less overuse of the common resource and more efficient use of the common resource. This is because social norms can make people feel obligated to use the resource in a sustainable manner, even if it means that they have to sacrifice some of their own short-term利益.

Social norms that can affect economic behavior include norms of reciprocity, norms of fairness, and norms of cooperation. Norms of reciprocity are norms that encourage people to return favors or benefits that they have received from others. Norms of fairness are norms that encourage people to treat others in a just and equitable manner. Norms of cooperation are norms that encourage people to work together to achieve common goals.

Social norms can be used to promote more efficient and sustainable economic outcomes by encouraging people to cooperate with each other, discouraging people from overusing common resources, and promoting norms of fairness and reciprocity.

Challenges to using social norms to promote more efficient and sustainable economic outcomes include the fact that social norms can be difficult to change, social norms can be different in different cultures, and social norms can be difficult to enforce.

It is important to consider social norms when designing economic policies because social norms can have a significant impact on economic behavior, social norms can help to promote more efficient and sustainable economic outcomes, and social norms can help to reduce inequality and poverty.

Economists can study social norms by conducting experiments, conducting surveys, observing behavior, and using a variety of other methods.