Perverse incentive

Last updated November 08, 2024

The phrase "perverse incentive" is often used in economics to describe an incentive structure with undesirable results, particularly when those effects are unexpected and contrary to the intentions of its designers.^[1]

Examples of perverse incentives
Electoral systems
Pest control campaigns
Community safety and harm reduction
Environmental and wildlife protection
Historic preservation schemes
Healthcare cost control
Humanitarian and welfare policies
Promotional schemes and public relations
Returns for effort
In literature
See also
References
Further reading

The Indian cobra Indiancobra.jpg — The Indian cobra

The results of a perverse incentive scheme are also sometimes called cobra effects. This name was coined by economist Horst Siebert based on an anecdote taken from the British Raj.^[2]^[3] The British government, concerned about the number of venomous cobras in Delhi, offered a bounty for every dead cobra. Initially, this was a successful strategy; large numbers of snakes were killed for the reward. Eventually, however, people began to breed cobras for the income. When the government became aware of this, the reward program was scrapped. The cobra breeders set their snakes free, leading to an overall increase in the wild cobra population.^[4]^[5]

Examples of perverse incentives

Electoral systems

A well-known example in social choice is perverse response,^[6] where a candidate can lose an election if the voters rank them higher. This occurs under single transferable vote and related systems (like primary elections and the two-round system),^[7].
The no-show paradox, a situation where a voter can help their preferred candidate by not showing up to vote for them, decreases the incentive to participate in many voting rules.

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.^[3] 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.^[8]
Experiencing an issue with feral pigs, the U.S. Army post of Fort Benning (now named Fort Moore) in Georgia offered hunters a $40-bounty for every pig tail turned in.^[9] 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^[10] 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.^[11]

Community safety and harm reduction

In 2002, British officials tasked with suppressing opium production in Afghanistan offered poppy farmers $700 an acre in return for destroying their crop. This ignited a poppy-growing frenzy among Afghan farmers, who sought to plant as many poppies as they could in order to collect payouts from the cash-for-poppies program. Some farmers harvested the sap before destroying the plants, getting paid twice for the same crop.^[12]
Gun buyback programs are carried out by governments to reduce the number of guns in circulation, by purchasing firearms from citizens at a flat rate (and then destroying them). Some residents of areas with gun buyback programs have 3D printed large numbers of crude parts that met the minimum legal definition of a firearm, for the purpose of immediately turning them in for the cash payout.^[13]^[14]
In 2021, the US Congress enacted stringent requirements to prevent sesame, a potential allergen, from cross-contaminating other foods. Many companies found it simpler and less expensive to instead add sesame directly to their product as an ingredient, exempting them from complying with the law.^[15]
In Alberta, under the Child, Youth and Family Enhancement Act, every person must report suspected child abuse to a director or police officer, and failure to do so is punishable by a $10,000 fine plus 6 months of imprisonment.^[16]^[17] However, according to criminal law professor Narayan, enforcing it would cause people to overreport, which wastes resources, and it would also create a chilling effect that prevents people from reporting child abuse observed over a period of time, as that would incriminate them for failing to report earlier.^[18] There are similar laws in other Canadian provinces.^[19]

Environmental and wildlife protection

The United States Endangered Species Act of 1973 imposes development restrictions on landowners who find endangered species on their property.^[20] While this policy has some positive effects for wildlife, it also encourages preemptive habitat destruction (draining swamps or cutting down trees that might host valuable species) by landowners who fear losing the lucrative development-friendliness of their land because of the presence of an endangered species.^[21] In some cases, endangered species may even be deliberately killed to avoid discovery.^[20]
In 2005 the UN Intergovernmental Panel on Climate Change began an incentive scheme to cut down on greenhouse gases. Companies disposing of polluting gases were rewarded with carbon credits, which could eventually get converted into cash. The program set prices according to how serious the damage the pollutant could do to the environment was and attributed one of the highest bounties for destroying HFC-23, a byproduct of a common refrigerant, HCFC-22. As a result, companies began to produce more of this refrigerant in order to destroy more of the byproduct waste gas, and collect millions of dollars in credits.^[22] This increased production also caused the price of the refrigerant to decrease significantly, motivating refrigeration companies to continue using it, despite the adverse environmental effects.^[23]^[24] In 2013, credits for the destruction of HFC-23 were suspended in the European Union.^[25]
In 2017, the Renewable Heat Incentive paid businesses to replace coal with renewable heating, typically bioenergy in the form of wood pellets. However, the subsidy for the energy was greater than its cost, which allowed businesses to make a profit simply by burning as much fuel as possible and heating empty buildings. The political fall-out caused the Northern Ireland Executive to collapse in 2017. It was not re-convened until 2020.^[26]^[27]

Historic preservation schemes

The United Kingdom's listed building regulations are intended to protect historically important buildings, by requiring owners to seek permission before making any changes to listed buildings. In 2017, the owners of an unlisted historic building in Bristol destroyed a 400-year-old ceiling the day before a scheduled visit by listings officers, allegedly to prevent the building from being listed, which could have limited future development.^[28]^[29]
The Tax Reform Act of 1976 provided for loss of tax benefits if owners demolished buildings. This led to an increase in arson attacks in the 1970s as a way of clearing land without financial penalties. The law was later altered to remove this aspect.^[30]

Healthcare cost control

Paying medical professionals and reimbursing insured patients for treatment but not prevention encourages medical conditions to be ignored until treatment is required.^[31] Moreover, paying only for treatment effectively discourages prevention (which would improve quality of life for the patient but would also reduce the demand for future treatments).
Payment for treatment generates a perverse incentive for unnecessary treatments. In 2015, a Detroit area doctor was sentenced to 45 years of prison for intentionally giving patients unnecessary cancer treatments, for which health insurance paid him at least 17.6 million dollars.^[32] Unnecessary treatment may harm in the form of side effects of drugs and surgery, which can then trigger a demand for further treatments themselves.
Medicare reimburses doctors at a higher rate if they administer more expensive medications to treat a condition. This creates an incentive for the physician to prescribe a more expensive drug when a less expensive one might do.^[33]

Humanitarian and welfare policies

In the 2000s, Canada negotiated a "Safe Third Country Agreement" with the U.S. under which applicants for political asylum could only apply in the first of the two countries they reached, in order to discourage asylum shopping. Among the provisions was one that denied anyone entering Canada at an official port of entry from requesting asylum there, in theory limiting asylum applications to either those filed by refugees in camps abroad or those who could legally travel to Canada and do so at an immigration office. In the late 2010s, some migrants began entering Canada illegally, between official border crossings, at places like Roxham Road between New York and Quebec, since once they were in Canada, they were allowed to file applications with the full range of appeals available to them, a process that could take years. Canada wound up processing thousands more applications for asylum than it had planned to.^[34]
The "welfare trap" theory describes perverse incentives that occur when money earned through part-time or minimum-wage employment results in a reduction in state benefits that would have been greater than the amount earned, thereby creating a barrier to low-income workers re-entering the workforce.^[35] According to this theory, underlying factors include a full tax exemption for public assistance while employment income is taxed; a pattern of welfare paying more per dependent child (while employers are prohibited from discriminating in this manner, and their workers often must purchase daycare); or loss of welfare eligibility for the working poor ending other means-tested benefits (public medical, dental, or prescription drug plans; subsidised housing; legal aid), which are expensive to replace at full market rates. If the withdrawal of means-tested benefits that comes with entering low-paid work causes there to be no significant increase in total income or even a net loss, then this gives a powerful disincentive to take on such work.^[36]

Promotional schemes and public relations

Hacktoberfest is an October-long celebration to promote contributions to the free and open-source software communities. In 2020, participants were encouraged to submit four or more pull requests to any public free or open-source (FOS) repository, with a free "Hacktoberfest 2020" T-shirt for the first 75,000 participants to do so.^[37] The free T-shirts caused frivolous pull requests on FOS projects.^[38]
Around 2010, online retailer Vitaly Borker found that online complaints about his eyeglass-sale website, DecorMyEyes, pushed the site to the top of Google searches and drove more traffic. He began responding to customer reports of poor quality and/or misfilled orders with insults, threats of violence, and other harassment.^[39] Borker continued writing toxic replies for a decade despite serving two separate sentences in U.S. federal prison over charges arising from them.^[40]

Returns for effort

The 20th-century paleontologist G. H. R. von Koenigswald used to pay Javanese locals for each fragment of hominin skull that they produced. He later discovered that the people had been breaking up whole skulls into smaller pieces to maximize their payments.^[41]
In building the first transcontinental railroad in the 1860s, the United States Congress agreed to pay the builders per mile of track laid. As a result, Thomas C. Durant of Union Pacific Railroad lengthened a section of the route, forming a bow shape and unnecessarily adding miles of track.^[42]
Funding fire departments by the number of fire calls that are made is intended to reward fire departments that do the most work. However, it may discourage them from fire-prevention activities, leading to an increase in actual fires.^[43]

In literature

In his autobiography, Mark Twain says that his wife, Olivia Langdon Clemens, had a similar experience:^[44]

Once in Hartford the flies were so numerous for a time, and so troublesome, that Mrs. Clemens conceived the idea of paying George a bounty on all the flies he might kill. The children saw an opportunity here for the acquisition of sudden wealth. ... Any Government could have told her that the best way to increase wolves in America, rabbits in Australia, and snakes in India, is to pay a bounty on their scalps. Then every patriot goes to raising them.

Related Research Articles

A heat pump is a device that consumes energy to transfer heat from a cold heat sink to a hot heat sink. Specifically, the heat pump transfers thermal energy using a refrigeration cycle, cooling the cool space and warming the warm space. In cold weather, a heat pump can move heat from the cool outdoors to warm a house ; the pump may also be designed to move heat from the house to the warmer outdoors in warm weather. As they transfer heat rather than generating heat, they are more energy-efficient than other ways of heating or cooling a home.

A subsidy, subvention or government incentive is a type of government expenditure for individuals and households, as well as businesses with the aim of stabilizing the economy. It ensures that individuals and households are viable by having access to essential goods and services while giving businesses the opportunity to stay afloat and/or competitive. Subsidies not only promote long term economic stability but also help governments to respond to economic shocks during a recession or in response to unforeseen shocks, such as the COVID-19 pandemic.

In general, incentives are anything that persuade a person or organization to alter their behavior to produce the desired outcome. The laws of economists and of behavior state that higher incentives amount to greater levels of effort and therefore higher levels of performance. For comparison, a disincentive is something that discourages from certain actions.

<span class="mw-page-title-main">Drug rehabilitation</span> Processes of treatment for drug dependency

Drug rehabilitation is the process of medical or psychotherapeutic treatment for dependency on psychoactive substances such as alcohol, prescription drugs, and street drugs such as cannabis, cocaine, heroin, and amphetamines. The general intent is to enable the patient to confront substance dependence, if present, and stop substance misuse to avoid the psychological, legal, financial, social, and medical consequences that can be caused.

The overjustification effect occurs when an expected external incentive such as money or prizes decreases a person's intrinsic motivation to perform a task. Overjustification is an explanation for the phenomenon known as motivational "crowding out". The overall effect of offering a reward for a previously unrewarded activity is a shift to extrinsic motivation and the undermining of pre-existing intrinsic motivation. Once rewards are no longer offered, interest in the activity is lost; prior intrinsic motivation does not return, and extrinsic rewards must be continuously offered as motivation to sustain the activity.

In the healthcare industry, pay for performance (P4P), also known as "value-based purchasing", is a payment model that offers financial incentives to physicians, hospitals, medical groups, and other healthcare providers for meeting certain performance measures. Clinical outcomes, such as longer survival, are difficult to measure, so pay for performance systems usually evaluate process quality and efficiency, such as measuring blood pressure, lowering blood pressure, or counseling patients to stop smoking. This model also penalizes health care providers for poor outcomes, medical errors, or increased costs. Integrated delivery systems where insurers and providers share in the cost are intended to help align incentives for value-based care.

Deinstitutionalisation is the process of replacing long-stay psychiatric hospitals with less isolated community mental health services for those diagnosed with a mental disorder or developmental disability. In the 1950's and 1960's, it led to the closure of many psychiatric hospitals, as patients were increasingly cared for at home, in halfway houses, group homes, and clinics, in regular hospitals, or not at all.

Fee-for-service (FFS) is a payment model where services are unbundled and paid for separately.

Share repurchase, also known as share buyback or stock buyback, is the reacquisition by a company of its own shares. It represents an alternate and more flexible way of returning money to shareholders. Repurchases allow stockholders to delay taxes which they would have been required to pay on dividends in the year the dividends are paid, to instead pay taxes on the capital gains they receive when they sell the stock, whose price is now proportionally higher because of the smaller number of shares outstanding.

An air source heat pump (ASHP) is a heat pump that can absorb heat from air outside a building and release it inside; it uses the same vapor-compression refrigeration process and much the same equipment as an air conditioner, but in the opposite direction. ASHPs are the most common type of heat pump and, usually being smaller, tend to be used to heat individual houses or flats rather than blocks, districts or industrial processes.

Patient dumping or homeless dumping is the practice of hospitals and emergency services inappropriately releasing homeless or indigent patients to public hospitals or on to the streets instead of transferring them to a homeless shelter or retaining them. These cases may usually require expensive medical care with minimal government reimbursement from Medicaid or Medicare. The term homeless dumping has been used since the late 19th century and resurfaced throughout the 20th century alongside legislation and policy changes aimed at addressing the issue. Studies of the issue have indicated mixed results from the United States' policy interventions and have proposed a variety of ideas to remedy the problem.

A gun buyback program is one instituted to purchase privately owned firearms. The goal of such programs is to reduce the circulation of both legally and illegally owned firearms. A buyback program would provide a process whereby civilians can dispose of illicitly owned firearms without financial loss or risk of prosecution. In most cases, the agents purchasing the guns are local police.

An incentive program is a formal scheme used to promote or encourage specific actions or behavior by a specific group of people during a defined period of time. Incentive programs are particularly used in business management to motivate employees and in sales to attract and retain customers. Scientific literature also refers to this concept as pay for performance.

<span class="mw-page-title-main">Pig farming</span> Raising and breeding of domestic pigs

Pig farming, pork farming, or hog farming is the raising and breeding of domestic pigs as livestock, and is a branch of animal husbandry. Pigs are farmed principally for food and skins.

In economics, a negative income tax (NIT) is a system which reverses the direction in which tax is paid for incomes below a certain level; in other words, earners above that level pay money to the state while earners below it receive money. NIT was proposed by Juliet Rhys-Williams while working on the Beveridge Report in the early 1940s and popularized by Milton Friedman in the 1960s as a system in which the state makes payments to the poor when their income falls below a threshold, while taxing them on income above that threshold. Together with Friedman, supporters of NIT also included James Tobin, Joseph A. Pechman, and Peter M. Mieszkowski, Jim Gray and even then-President Richard Nixon, who suggested implementation of modified NIT in his Family Assistance Plan. After the increase in popularity of NIT, an experiment sponsored by the US government was conducted between 1968 and 1982 on effects of NIT on labour supply, income, and substitution effects.

Capitation is a payment arrangement for health care service providers. It pays a set amount for each enrolled person assigned to them, per period of time, whether or not that person seeks care. The amount of remuneration is based on the average expected health care utilization of that patient, with payment for patients generally varying by age and health status.

The lunatic asylum, insane asylum or mental asylum was an institution where people with mental illness were confined. It was an early precursor of the modern psychiatric hospital.

A bug bounty program is a deal offered by many websites, organizations, and software developers by which individuals can receive recognition and compensation for reporting bugs, especially those pertaining to security exploits and vulnerabilities.

Rodent farming is an agricultural process in which rodents are bred and raised with the intent of selling them for their meat. They are often categorised in a sub-category of livestock known as micro-livestock, due to their small size. Rodents have been used as food in a wide range of cultures, including Hawaiian, Vietnamese, French, Indian and Thai.

The Great Hanoi Rat Massacre occurred in 1902, in Hanoi, Tonkin, French Indochina, 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. 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.

References

↑ Brickman, Leslie H. (2002). Preparing the 21st Century Church. Xulon Press. p. 326. ISBN 978-1591601678.
↑ Siebert, Horst (2001). Der Kobra-Effekt. Wie man Irrwege der Wirtschaftspolitik vermeidet (in German). Munich: Deutsche Verlags-Anstalt. ISBN 3421055629.
1 2 Dubner, Stephen J. (11 October 2012). "The Cobra Effect: A New Freakonomics Radio Podcast". Freakonomics, LLC. Retrieved 24 February 2015.
↑ Schwarz, Christian A. (1996). NCD Implementation Guide. Carol Stream Church Smart Resources. p. 126. Cited in Brickman, p. 326.
↑ Coy, Peter (26 March 2021). "Goodhart's Law Rules the Modern World. Here Are Nine Examples". Bloomberg.com. Retrieved 12 January 2023.
↑ Spenkuch, Jörg L. (2012). "Please Don't Vote for Me: Strategic Voting in a Natural Experiment with Perverse Incentives". SSRN Electronic Journal. doi:10.2139/ssrn.2047221. ISSN 1556-5068.
↑ Doron, Gideon; Kronick, Richard (1977). "Single Transferrable Vote: An Example of a Perverse Social Choice Function". American Journal of Political Science. 21 (2): 303–311. doi:10.2307/2110496. ISSN 0092-5853.
↑ Doron, Gideon; Kronick, Richard (1977). "Single Transferrable Vote: An Example of a Perverse Social Choice Function". American Journal of Political Science. 21 (2): 303–311. doi:10.2307/2110496. ISSN 0092-5853.
↑ "Fort Benning puts a bounty on boars". NBC News. Associated Press. 1 March 2008.
↑ Animal and Plant Health Inspection Service (27 May 2015). "Chapter 2: Alternatives; Section 2. Methods Dismissed" (PDF). Feral Swine Damage Management: A National Approach. U.S. Department of the Interior Fish and Wildlife Service; U.S. Department of Agriculture Natural Resource Conservation Service. United States Department of Agriculture, APHIS. p. 78. Final Environmental Impact Statement. Archived from the original (PDF) on 20 May 2023.
↑ Ditchkoff, Stephen S.; Holtfreter, Robert W.; Williams, Brian L. (September 2017). "Effectiveness of a bounty program for reducing wild pig densities". Wildlife Society Bulletin. 41 (3): 548–555. Bibcode:2017WSBu...41..548D. doi: 10.1002/wsb.787 .
↑ Whitlock, Craig (2021). The Afghanistan Papers: A Secret History of the War. Simon and Schuster. p. 136. ISBN 978-1982159023.
↑ Rose, Janus (2 August 2022). "Someone Made $3,000 Selling 3D-Printed Guns at a Gun Buyback Event". Vice . Archived from the original on 2 August 2022.
↑ "Participant used a 3D printer to make firearm parts in bulk that he then exchanged for gift cards". The Guardian . Associated Press. 11 October 2022.
↑ Aleccia, Jonel (21 December 2022). "New label law has unintended effect: Sesame in more foods". Associated Press.
↑ "RSA 2000, c C-12 | Child, Youth and Family Enhancement Act". CanLII. 1 April 2023. Retrieved 14 March 2024.
↑ Johnston, Janice (30 October 2019). "Serenity's Law receives royal assent". Canadian Broadcasting Corporation . Retrieved 14 March 2024.
↑ Graveland, Bill (1 October 2017). "Alberta urged to enforce law on child abuse reporting". Canadian Broadcasting Corporation . Retrieved 14 March 2024.
↑ Rimer (10 April 2019). "INFORMATION SHEET #7 SUMMARY OF LEGAL REQUIREMENTS FOR REPORTING SUSPICIONS OF CHILD ABUSE" (PDF). Retrieved 14 March 2024.
1 2 Langpap, Christian, and JunJie Wu. 2017. "Thresholds, Perverse Incentives, and Preemptive Conservation of Endangered Species" Journal of the Association of Environmental and Resource Economists 4(S1):S227–S259. doi : 10.1086/692070.
↑ Stephen Dubner and Steven Levitt, Unintended Consequences, New York Times Magazine, 20 January 2008
↑ "The Cobra Effect". Freakonomics. Archived from the original on 18 October 2012.
↑ Rosenthal, Elisabeth; Lehren, Andrew W. (8 August 2012). "Incentive to Slow Climate Change Drives Output of Harmful Gases". The New York Times. ISSN 0362-4331 . Retrieved 2 July 2015.
↑ Gupta, Anika. "Carbon credit scam slur on Indian firms". Hindustan Times. Archived from the original on 4 July 2015. Retrieved 2 July 2015.
↑ "Commission adopts ban on the use of industrial gas credits". Climate Action. European Commission. 23 November 2016. Retrieved 3 November 2019.
↑ "RHI scandal: RHI 'cash for ash' scandal to cost NI taxpayers £490m". BBC News . 23 December 2016.
↑ "Stormont crisis: Deadline passes for future of executive". BBC. BBC News. 16 January 2017.
↑ "Bristol Jacobean ceiling 'destroyed before listings visit'". BBC News. 1 September 2017.
↑ "Press release: Developer mutilates Jacobean ceiling to avoid potential listing". Save Britain's Heritage. 31 August 2017.
↑ Newcomb, Amelia A. (21 May 1982). "Historic buildings prove special target for arson". Christian Science Monitor. ISSN 0882-7729 . Retrieved 13 January 2023.
↑ Robinson, JC (21 April 2004). "Reinvention of health insurance in the consumer era". JAMA . 291 (15): 1880–6. doi:10.1001/jama.291.15.1880. PMID 15100208.
↑ Moghe, Sonia (11 July 2015). "Patients give horror stories as cancer doctor gets 45 years". CNN. Retrieved 4 November 2024.
↑ Sanger-katz, Margot (10 March 2016). "Medicare Tries an Experiment to Fight Perverse Incentives". The New York Times. ISSN 0362-4331 . Retrieved 30 July 2016.
↑ Keller, Tony (12 July 2018). "Canada Has Its Own Ways of Keeping Out Unwanted Immigrants". The Atlantic . Retrieved 30 June 2021.
↑ "Gassing up the welfare trap machine -". Atlantic Institute for Market Studies. 6 January 1997. Retrieved 13 January 2023.
↑ Baetjer, Howard (24 August 2016). "The Welfare Cliff and Why Many Low-Income Workers Will Never Overcome Poverty". Learn Liberty.
↑ "Hacktoberfest 2020". Laravel News. 25 September 2020. Retrieved 31 January 2021.
↑ Claburn, Thomas (1 October 2020). "Open-source devs drown in DigitalOcean's latest tsunami of pull-request spam that is Hacktoberfest". The Register . Retrieved 29 February 2024.
↑ David Segal (26 November 2010). "For DecorMyEyes, Bad publicity is a good thing". New York Times.
↑ Segal, David (2 May 2021). "Has Online Retail's Biggest Bully Returned?". The New York Times . Retrieved 3 May 2021.
↑ III, Carl C. Swisher; Curtis, Garniss H.; Lewin, Roger (2001). Java Man: How Two Geologists Changed Our Understanding of Human Evolution. University of Chicago Press. ISBN 978-0226787343.
↑ Mark Zwonitzer, writer, PBS American Experience documentary "Transcontinental Railroad" (2006) "Program Transcript . Transcontinental Railroad . WGBH American Experience" Archived 30 January 2017 at the Wayback Machine
↑ Department for Communities and Local Government (2002). "Fire" Archived 2004-08-01 at the Wayback Machine . In Consultation on the Local Government Finance Formula Grant Distribution. Retrieved 10 November 2006.
↑ Mark Twain (2010), Michael J. Kiskis (ed.), Mark Twain's Own Autobiography: The Chapters from the North American Review, University of Wisconsin Press, pp. 151–152, ISBN 978-0299234737