Public goods, private goods and quasi-public goods

Public goods

Non-excludable and non-rival good that is not diminishable when someone else uses it and is funded through taxation.

Public good example

Street lights

Public good problem

Free-rider problem which means people who pay for it and people who don’t receive the same benefit from the good.

Private goods

Rival and excludable

Private good example

Chocolate bar as it can only be consumed by one consumer

Quasi public good

Semi-excludable and semi-non-rival

Quasi public good example

Tolls as most people can use it unless rush hour