This is because of a very basic economic concept called "externalities": https://en.wikipedia.org/wiki/Externality https://en.wikipedia.org/wiki/Externality Ve

This is because of a very basic economic concept called "externalities": https://en.wikipedia.org/wiki/Externality https://en.wikipedia.org/wiki/Externality Very simply: Not all costs are included in the production costs of a good or service, they are external. For example, the producer usually does not pay the full cost of emitting CO2 when producing something. The remaining cost of born by the public, in the form of environmental damage, health issues, and so on. There are many other externalities, like social (e.g. by exploiting workers, you can produce something cheaper).