Marks and Grades: the Hanoi Rat Massacre, the ‘Cobra Effect’, and Education

Arnold Mascarenhas
4 min readSep 1, 2021


Rats, cobras, and the education system. Would you have ever imagined these three words together in the same statement? Probably not!

Story time…

Back in the early 1900s when the French ruled Hanoi in Vietnam, there were sanitation issues in the region. One of the major concerns was the rat infestation in the sewers that appeared to be carrying the plague.

The French had a supposedly genius idea: Let’s get the poor citizens to hunt the rats. Then we reward them for each rat caught. In order to avoid a costly storage and disposal issue, they offered a reward for each rat tail presented.

The citizens of Hanoi began submitting rat tails in abundance; but did that mean the project was a success?

The project was an apparent success. Rat tails began pouring in. However, the number of rodents roaming the streets didn’t seem to have come down. As it turned out, the cheeky citizens had begun catching rats, but instead of killing them, they were merely chopping their tails off for the reward and setting them free. They then left the rats to continue mating and growing the population.

There were even reports of folks intentionally breeding rats on farms to capitalize on the rat-tail reward. Some even imported them from neighbouring countries!

This phenomenon was termed as ‘The Cobra Effect’ (also known as the ‘perverse incentive’). This is because a similar incident had happened in colonial India with the British and cobras (instead of rats).

The ‘Cobra Effect’ is an idea under economic and management practice that tries to explain how incentives can go wrong. Not only can they fail, but in fact, have the opposite effect.

Where do we see the ‘Cobra Effect’?

If we look carefully, we can see ‘the Cobra Effect’ in everyday life and business. Here are a few examples.

  • Employees striving to meet quotas to capture their bonus by using short-sighted tactics
  • Corporate executives using creative accounting to meet short-term and quarterly targets to appease the boards and shareholders instead of prioritizing long-term value and generating sustainable growth
  • And finally, students studying to get maximum marks instead of studying with the intent of learning and building a critical, thinking mind

The ‘Cobra Effect’ in education

The fault in the last case actually lies not with the student, but with the entire education ecosystem (the parents, teachers, and schools).

Students are tested to evaluate how well they have ingested the material. However, because of the way the tests are structured, students simply need to replicate the textbook material during exams.

As a result, the understanding and widening of minds does not take place. Rote learning and memorization (aka ‘catching rat tails’) is a higher priority, but the marks and grades only measure how well they can recall the concepts. They do not require students to explain or apply them in any way.

Each stakeholder in the education ecosystem is invested in student “learning”, which is completely determined by the marks or grades students obtain.

Beyond schools, there is a whole industry of coaching institutes, private tutors, and (most recently) ed-tech companies. These exist primarily to help students game the system and maximize rat tails grades and marks.

So, what exactly is the ‘cobra effect’ in the education system? How do the incentives of marks and grades fail?

As a result of over-dependence on marks and grades gained from memorization, children don’t end up learning the real-world skills needed to understand and apply these concepts. It’s no wonder that our graduates are so highly unemployable. We aren’t teaching to build our young minds. We’re just capturing tails to meet short-term objectives.

The current mainstream schooling system fails to address the life skills that are relevant to everyday functioning as adults in society.

To conclude…

Measurement of learning in some form or the other is desirable. However, it is the over-reliance on grades as a measure of intelligence and academic success that is the bigger and real problem.

children, education and learning concept - sad student boy with failed school test at home
Education has been reduced to academic learning outcomes in the form of marks and grades

The rat tails that are our grades, marks, and even degrees come to naught in getting us equipped to solve real-world problems.

It’s high time we expand the definition and purpose of education. The aims of education should be to empower individuals and to create a better-functioning society with improved outcomes on all fronts.



Arnold Mascarenhas

Lokyatha is an education focused initiative to enable young adults to live better, more fruitful lives by delivering real world life skills.