Externality:An externality is a cost or benefit that affects a party who did not choose to incur that cost or benefit. Pollution is a negative externality, where the costs of production are borne by society rather than the producer.
Tragedy of the Commons:The tragedy of the commons refers to a situation where individuals, acting independently and rationally according to their own self-interest, will ultimately deplete or destroy a shared resource, even when it is not in anyone's long-term interest for this to happen.
Environmental Regulation: Environmental regulation refers to the laws, policies, and guidelines put in place by governments to control and mitigate the negative impacts of pollution and other environmental issues.