The goal is to ensure that the costs and benefits of the activity are reflected in the prices paid by the participants, rather than being imposed on third parties who are not part of the transaction. This can be achieved through various means, such as taxes, subsidies, regulations, or market-based mechanisms such as emissions trading.

Examples of internalizing externalities include:

1. Carbon pricing: A tax on carbon emissions or a cap-and-trade system that allows firms to buy and sell permits for emissions, with the goal of reducing greenhouse gas emissions.
2. Pollution control regulations: Limits on the amount of pollutants that firms can emit, with the goal of reducing environmental damage and preserving public health.
3. Pay-as-you-throw programs for waste management: A system in which households pay for waste disposal based on the amount of waste they generate, incentivizing them to reduce their waste production.
4. User fees for public goods and services: A fee charged to individuals or businesses who use public goods or services, such as parks or roads, with the goal of recovering the cost of the service.

Internalising externalities helps to create a more efficient and equitable allocation of resources by ensuring that the costs and benefits of economic activities are reflected in the prices paid by the participants, rather than being imposed on third parties.