Editing Public bad

{{Short description|Concept in economics}}
{{more citations needed|date=October 2007}}
[[File:Pollution de l'air.jpg|thumb|right|230px|Air pollution is an example of a public bad.]]
A '''public bad''', in [[economics]], is the symmetrical opposite of a [[Public good (economics)|public good]]. [[Air pollution]] is the most obvious example since it is non-excludable and non-rival, and negatively affects welfare.<ref>For current definitions of public bads see: Charles D. Kolstad, ''Environmental Economics'' Second Edition {{ISBN|0-19-973264-7}}.</ref>

Whereas public goods are typically under-provided by decentralized decision making (the market), public bad will generally be over-provided, since the parties generating the public bad do not account for the negative effects (or [[externality]]) imposed on others. One possibility to mitigate the existence of public bad is the intervention of a third party, typically the state.

In "[[green economics]]", it is a [[Good (economics)|good]] that produces socially undesirable results (or an externality in standard economics). Most "green economists" advise [[measuring]] such impacts back to the present from the [[Seven generation sustainability|seventh generation]].  Thus in the golf course example, both the recreation and the negative impacts from deforestation, associated [[habitat (ecology)|habitat]] and [[biodiversity loss]], and [[pesticide]] toxicity would be estimated across those generations and some [[Amortization (accounting)|amortization]] applied to determine whether the golf course was a [[public benefit]] or a public bad from the point of view of that seventh generation.

Green economists argue that the costs of public bads are [[hidden cost|hidden]] as [[externality|externalities]] from the businesses that cause them &mdash; meaning the market is not working correctly. The legal challenge is to create a system that takes into account these costs. The [[United States Environmental Protection Agency]] is an example of an attempt to make sure the costs of public bads are taken into account, although some groups on the right and left have criticized the value of its efforts.

==See also==
*[[Externality]]
*[[Social cost]]

== References ==
{{Reflist}}

{{DEFAULTSORT:Public Bad}}
[[Category:Welfare economics]]
[[Category:Public sphere|Bad]]