Critical Thinking

Misguided Motivations: The Folly of Incentives in the Great Hanoi Rat Massacre

In the late 18th century, Governor Paul Doumer of the French colonial government had a vision to modernize Hanoi. His plan included the introduction of toilets, which unfortunately attracted disease-spreading rats. As time passed, the rat population became a growing concern. In a desperate attempt to control the vermin invasion, the government launched a program that rewarded citizens for every rat tail they brought in, hoping to reduce the rat numbers. However, this seemingly brilliant solution turned into a catastrophic event.

Unbeknownst to the government, the citizens of Hanoi discovered a loophole in the system. Instead of exterminating the rats, they started amputating the rats’ tails without killing them. This allowed the rats to continue to breed more rats with tails, as these would become a future source of income.

The situation quickly descended into utter madness. Driven by insatiable greed, some individuals established rat-breeding farms to maximize their rewards, while others resorted to importing rat tails from distant regions. The unintended consequence of this perverse incentive scheme was a massive explosion in the rat population, exacerbating the very problem it was meant to solve.

This ill-fated event, known as the “Great Hanoi Rat Massacre,” is a notorious example of the dangers of perverse incentives.

The Unintended Consequences of Incentive-driven Actions

In his insightful book, Mixed Signals: How Incentives Really Work (2023,) Uri Gneezy, a distinguished behavioral economist from the University of California-San Diego, masterfully presents compelling examples that highlight the profound disparity between the intended behaviors incentives aim to promote and the unforeseen behaviors they unintentionally trigger. Gneezy’s astute analysis illuminates the perplexing nature of these gaps, offering invaluable insights into the actual workings of incentive systems. Another example of this point is the situation with many doctors operating under Fee for Service (FFS) payment models. In these models, doctors are incentivized to perform additional tests and procedures to increase their own payment. As a result, their focus may shift from promoting overall health to simply recommending more procedures.

To avoid sending confusing messages through incentives, Gneezy emphasizes the importance of carefully considering such initiatives’ potential outcomes and unintended effects. Gneezy strongly advocates for the use of prototype incentive programs.

Consider the case of the Wells Fargo cross-selling scandal, which was caused by aggressive sales practices. To increase the number of accounts held by existing customers, the company decided to motivate bank employees to promote additional services, like credit cards and savings accounts, to customers with checking accounts. However, due to a lack of proper oversight, employees resorted to fraudulent practices by creating over three million unauthorized credit card accounts without customers’ knowledge or consent. These unethical practices harmed customers who ended up with unwanted and unnecessary accounts, violated their trust, and exposed them to fees and penalties. In order to prevent such a scandal, Wells Fargo could have implemented prototype techniques and established an auditing system to verify the legitimacy of accounts randomly.

The Irony of Fines as Deterrents in Action

Gneezy brilliantly dissects the flawed notion that imposing fines is a universal remedy. He highlights how fines, often intended as deterrents, can backfire by diverting people’s focus from deterring behavior to merely avoiding punishment. For instance, when drivers are warned about the perils of texting while driving, they may genuinely reflect on the risks involved and the value of their own lives. However, the introduction of a $500 fine shifts their mindset. Now, their attention shifts from personal safety to the likelihood of encountering law enforcement. If they perceive a lack of police presence, the thought process changes to “No police around, no risk of getting caught—time to text!” In this way, the imposition of fines skews individuals’ attention from contemplating potential hazards to the probability of facing the consequences.

Recommendation: Fast-read Mixed Signals: How Incentives Really Work (2023.) Greezly’s work serves as a resounding reminder that designing an incentive system to encourage desired behavior while minimizing unintended consequences is no easy feat. Greezly’s advice on balancing multiple metrics to avoid the pitfalls of fixating on a single metric at the expense of others and the importance of regularly reviewing and updating the system while keeping a vigilant eye on unintended consequences is undeniably accurate.