An externality is a situation where the actions of one party impose costs or benefits on another party without compensation.

A negative externality is a situation where the actions of one party impose costs on another party without compensation. Pollution is a classic example of a negative externality.

A positive externality is a situation where the actions of one party confer benefits on another party without compensation. Planting trees is an example of a positive externality, as it provides benefits such as cleaner air and improved water quality.

Depletion is the term used to describe the situation where a resource is used up faster than it can be replenished.

A renewable resource is a resource that can be replenished naturally. Solar energy is a renewable resource, as it is derived from the sun.

A non-renewable resource is a resource that cannot be replenished naturally. Fossil fuels, such as oil, coal, and natural gas, are non-renewable resources.

Total Economic Value (TEV) is the term used to describe the value that people place on a good or service, taking into account both its direct and indirect benefits.

A direct benefit is a benefit that is directly derived from the use of a good or service. The enjoyment of using a good or service is a direct benefit.

An indirect benefit is a benefit that is not directly derived from the use of a good or service, but rather from its effects on other things. The increased productivity of a worker is an indirect benefit of education.

Economic efficiency is the term used to describe the situation where the benefits of a good or service exceed its costs.

A market failure is a situation where the market does not allocate resources efficiently. A monopoly is an example of a market failure, as it allows a single firm to control the market and charge higher prices than would be the case in a competitive market.

A public good is a good or service that is non-rival and non-excludable. This means that once a public good is produced, it can be enjoyed by everyone, regardless of whether or not they pay for it.

A public good is a good or service that is non-rival and non-excludable. National defense is an example of a public good, as it benefits everyone in society, regardless of whether or not they pay for it.

A common good is a good or service that is rival but non-excludable. This means that once a common good is produced, it can be enjoyed by everyone, regardless of whether or not they pay for it, but it is also possible to exclude people from enjoying the good or service.

A common good is a good or service that is rival but non-excludable. A fishing spot is an example of a common good, as it can be enjoyed by everyone, regardless of whether or not they pay for it, but it is also possible to exclude people from fishing in the spot.