Global InformationGreat Hanoi Rat Massacre information
 A French Indochinese 1 cent coin from 1902, which was offered as a reward per rat's tail. | |
| Native name | Cuộc đại thảm sát chuột ở Hà Nội (局大慘殺𤝞於河內) Grand massacre des rats de Hanoï |
|---|---|
| Date | 1902 (Thành Thái 14 / 成泰十四年)[a] |
| Location | Hanoi, Tonkin, French Indochina (present day Hanoi, Vietnam) |
| Also known as | The Great Hanoi Rat Hunt |
| Type | Rat extermination campaign |
| Cause | Third plague pandemic, expansion of the Hanoian rat population due to the expansion of Hanoi's French Quarter. |
| Motive | To prevent a potential outbreak of the Bubonic Plague caused by the Yersinia pestis bacteria. |
| Target | Rats |
| Participants | Government-General of French Indochina, professional rat-catching services, and vigilante rat hunters |
| Outcome | Bounty programme cancelled, other anti-pandemic measures taken. |
| Casualties | |
| Hundreds of thousands of rats (reported between April and June 1902) Unknown number of rats afterwards. | |
| Awards | 1 cent per rat's tail |
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| History of Hanoi |
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| Timeline |
 Vietnam portal |
The Great Hanoi Rat Massacre (Vietnamese: Cuộc đại thảm sát chuột ở Hà Nội; chữ Nôm: 局大慘殺𤝞於河內; French: Massacre des rats de Hanoï) occurred in 1902, in Hanoi, Tonkin, French Indochina (present day Hanoi, Vietnam), when the French government authorities attempted to control the rat population of the city by hunting them down. As they felt that they were making insufficient progress, and due to labour strikes, they created a bounty programme that paid a reward of 1¢ for each rat killed.[1] 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 catchers would capture rats, sever their tails, then release them back into the sewers so that they could produce more rats.[2]
The Great Hanoi Rat Massacre happened in the middle of a global pandemic only a few years after Swiss-French physician and bacteriologist Alexandre Yersin linked the spread of the pandemic to rodents.[3]
Today, the events are often used as an example of a perverse incentive, commonly referred to as the Cobra Effect.[1] The modern discoverer of this event, American historian Michael G. Vann argues that the cobra example from the British Raj cannot be proven, but that the rats in Vietnam case can be proven, so the term should be changed to the Rat Effect.[1]
- ^ a b c Dubner, Stephen J. (11 October 2012). "The Cobra Effect: A New Freakonomics Radio Podcast". Freakonomics, LLC. Archived from the original on 13 October 2012. Retrieved 24 February 2015.
- ^ Vann, Michael G. (2003). "Of Rats, Rice, and Race: The Great Hanoi Rat Massacre, an Episode in French Colonial History". French Colonial History. 4: 191–203. doi:10.1353/fch.2003.0027. S2CID 143028274.
- ^ Yersin, Alexandre (1894). "La peste bubonique à Hong-Kong" [The Bubonic Plague in Hong Kong]. Annales de l'Institut Pasteur (in French). 8: 662–667.