Fact checked by Pete Rathburn
Reviewed by David Kindness
What Are Externalities?
An externality is a cost or benefit related to the production or consumption of a good or service that affects third parties unrelated to the production or consumption. It is generally the unintended, indirect consequence of everyday economic activities.
Externalities occur when the transactions between two parties affect the existence and well-being of a third. In economics, there are four different types of externalities:
- Positive consumption
- Positive production
- Negative consumption
- Negative production
As implied by their names, externalities can have positive or negative effects.
Read on to learn how externalities affect equilibrium and market failure.
Key Takeaways
- An externality is a cost or benefit to an unrelated third party that stems from the production or consumption of a good or service.
- Equilibrium is the ideal balance between buyers’ benefits and producers’ costs
- Market failure is the inefficient distribution of goods and services in the market.
- Externalities lead to market failure because a product or service’s price equilibrium does not accurately reflect the true costs and benefits of that product or service.
Understanding Externalities
Externalities, which can be both positive or negative, can affect an individual or single entity, or they can affect society as a whole.
Those impacted by externalities—usually third parties—have no control over them and never choose to incur the costs or benefits.
It is primarily the responsibility of those generating externalities to account for them and manage them as much as possible.
Negative Externalities
Negative externalities usually come at a cost to individuals, while positive externalities generally provide a benefit.
For example, a crematorium releases toxic gases such as mercury and carbon dioxide into the air. This has a negative impact on people who may live in the area, causing them harm.
Pollution is another commonly known negative externality. Corporations and industries may try to curb their costs by using production measures that have a detrimental effect on the environment. While this may decrease the cost of production and increase revenues, it also imposes a cost on the environment and society.
Positive Externalities
Meanwhile, establishing more green spaces in a community brings more benefits to those living there.
Another positive externality is the investment in education. When education is easy to access and affordable, society benefits as a whole. People with an education can command higher wages, while employers have a labor pool that’s knowledgeable and trained.
Governments may choose to remove or reduce negative externalities through taxation and regulation. So, heavy polluters, for example, may be taxed and subject to more scrutiny.
Those who create positive externalities, on the other hand, may be rewarded with subsidies.
Important
Governments that regulate in an attempt to curb negative externalities must be prepared to monitor the producers and to hold those who fail to improve accountable.
Equilibrium and Market Failure
Externalities lead to market failure when a product or service’s price equilibrium does not accurately reflect the true costs and benefits of that product or service.
Equilibrium represents the ideal balance between buyers’ benefits and producers’ costs. It is supposed to result in the optimal level of production.
However, the equilibrium level is flawed when there are significant externalities, which create incentives that drive individual actors to make decisions which end up making the group worse off. This is known as a market failure.
When negative externalities are present, it means the producer does not bear all costs, which results in excess production.
With positive externalities, the buyer alone does not get all the benefits of the good; others benefit, too. This results in decreased production.
Negative Externality Example
Let’s look at a negative externality example of a factory that produces widgets. It pollutes the environment during the production process. The cost of the pollution is not borne by the factory, but is instead imposed upon and shared by society.
If the negative externality were taken into account, then the cost of the widget would be higher. This would result in decreased production and a more efficient price equilibrium.
In this case, though, the market failure was too much production and a price that didn’t match the true cost of production, as well as high levels of pollution.
Positive Externality Example
Now let’s take a a look at the relationship between positive externalities and market failure. Take education. Obviously, the person being educated benefits from and pays for this cost.
However, there are positive externalities beyond the one person being educated. These could be a more intelligent and knowledgeable citizenry, increased tax revenues from better-paying jobs, less crime, and more social stability.
All of these factors positively correlate with education levels. These benefits to society are not accounted for when the consumer considers the benefits of education.
Therefore, education would be under-consumed relative to its equilibrium price level if these benefits are taken into account.
Clearly, public policymakers should look to subsidize markets with positive externalities and punish those with negative externalities.
Note
Market failure occurs when the balance between supply and demand is upset and price equilibrium disappears. It reflects the inefficient allocation of resources.
Obstacles to Overcoming Externalities and Correcting Market Failure
One obstacle for policymakers in their efforts to correct market failures is the difficulty of quantifying externalities to increase or decrease consumption or production.
In the case of pollution, policymakers have tried tools, including mandates, incentives, penalties and taxes, that would result in increased costs of production for companies that pollute.
For education, policymakers have looked to increase consumption with subsidies, access to credit, and public education.
Moreover, in addition to positive and negative externalities, some other reasons for market failure include a lack of public goods, under-provision of goods, overly harsh penalties, and monopolies.
The upshot is that markets are the most efficient way to allocate resources, with the assumption that all costs and benefits are accounted for by prices.
When this is not the case, significant costs are inflicted upon society, as a result of underproduction or overproduction.
Can Markets Correct Externalities?
This is a topic of debate. They sometimes can, especially if the externality is small scale and the parties to the transaction can work out a fix. However, with major externalities, the government usually gets involved due to its ability to make the required impact.
When Do Externalities Happen?
They happen when the costs or benefits of an economic transaction between a producer and a consumer aren’t restricted just to them but indirectly affect other people.
What’s Government’s Role in Affecting Externalities?
A government can curb negative externalities by taking steps to tax the goods and services that are causing costs to affect uninvolved third parties. Conversely, it can support positive externalities by providing subsidies for the goods and services that affect third parties.
The Bottom Line
Being cognizant of externalities is one important step in combating market failure.
While price discovery and resource allocation mechanisms of markets need to be respected, market equilibrium is a balance between costs and benefits to the producer and consumer. It does not take third parties into account.
Thus, it is policymakers’ responsibility to adjust costs and benefits in an optimal way.