Editing Perverse incentive (section)

=== Pest control campaigns ===

* The [[Great Hanoi Rat Massacre]] occurred in 1902, in [[Hanoi]], [[Vietnam]] (then known as [[French Indochina]]), when, under French colonial rule, the colonial government created a bounty program that paid a reward for each [[rat]] killed.<ref name="freak22" /> To collect the bounty, people would need to provide the severed tail of a rat. Colonial officials, however, began noticing rats in Hanoi with no tails. The Vietnamese [[Rat-catcher|rat catchers]] would capture rats, sever their tails, then release them back into the sewers so that they could produce more rats.<ref name=":0">{{Cite journal |last1=Doron |first1=Gideon |last2=Kronick |first2=Richard |date=1977 |title=Single Transferrable Vote: An Example of a Perverse Social Choice Function |url=https://www.jstor.org/stable/2110496 |journal=American Journal of Political Science |volume=21 |issue=2 |pages=303–311 |doi=10.2307/2110496 |jstor=2110496 |issn=0092-5853}}</ref>
* Experiencing an issue with [[Feral pig|feral pigs]], the [[United States Army|U.S. Army]] post of [[Fort Benning]] in [[Georgia (U.S. state)|Georgia]] offered hunters a $40-bounty for every pig tail turned in.<ref>{{cite news |date=1 March 2008 |title=Fort Benning puts a bounty on boars |url=https://www.nbcnews.com/id/wbna23416106 |work=NBC News |language=en |agency=Associated Press}}</ref> Over the course of the 2007–2008 program, the feral pig population in the area increased. While there were some reports that individuals purchased pigs' tails from meat processors<ref name="aphis2">{{cite book |author1=((Animal and Plant Health Inspection Service)) |author1-link=Animal and Plant Health Inspection Service |title=Feral Swine Damage Management: A National Approach |date=27 May 2015 |publisher=United States Department of Agriculture, APHIS |others=U.S. Department of the Interior Fish and Wildlife Service; U.S. Department of Agriculture Natural Resource Conservation Service |page=78 |chapter=Chapter 2: Alternatives; Section 2. Methods Dismissed |id=Final Environmental Impact Statement |chapter-url=https://www.aphis.usda.gov/wildlife_damage/nepa/states/US/us-2015-fs-damage-mgt-a-national-approach-eis.pdf |archive-url=https://web.archive.org/web/20230520155519/https://www.aphis.usda.gov/wildlife_damage/nepa/states/US/us-2015-fs-damage-mgt-a-national-approach-eis.pdf |archive-date=20 May 2023}}</ref> then resold the tails to the Army at the higher bounty price, a detailed study of the bounty scheme found different effects from perverse incentives were mainly responsible. Both the pigs' fertility rate and offspring survival rates increased under the scheme. This was due to improved nutrition made available by the feed bait used to attract the animals to hunting sites. Secondly, hunters were found to be more likely to preferentially target large males as "trophy"-quality game, while ignoring females and juveniles as targets. Removal of mature males from the population has a negligible impact on population growth, as remaining mature males can each stud many breeding sows.<ref>{{cite journal |last1=Ditchkoff |first1=Stephen S. |last2=Holtfreter |first2=Robert W. |last3=Williams |first3=Brian L. |date=September 2017 |title=Effectiveness of a bounty program for reducing wild pig densities |journal=Wildlife Society Bulletin |volume=41 |issue=3 |pages=548–555 |bibcode=2017WSBu...41..548D |doi=10.1002/wsb.787 |doi-access=free}}</ref>