The Great Hanoi Rat Bounty

In the early 1900s, Hanoi was the jewel of French Indochina — a colonial city reimagined in the image of Paris. Wide boulevards, ornate facades, a European-style opera house. And underneath it all, a newly installed sewer system meant to showcase the modern brilliance of French engineering.

Unfortunately, it also became a rat utopia.

The sewers were warm, damp, and filled with refuse — ideal conditions for a booming rat population. As reports of plague spread across parts of Asia, French officials in Hanoi feared the worst. The rats had to go.

So, they turned to a classic tactic: a bounty.

The plan was simple. Pay locals a small fee for every rat killed. To keep things tidy, the authorities decided they wouldn’t collect whole carcasses — just the tails.

At first, it seemed to work.
Tails came in by the thousands. Officials paid out the rewards. The rat sightings slowed.

But soon, they started noticing something strange: rats without tails — alive and running freely through the city.

It didn’t take long to figure out what had happened.

People were cutting off the tails and letting the rats go — so they could breed, produce more rats, and keep the tail-supply flowing.

Even worse, some enterprising individuals began breeding rats outright, running makeshift rat farms to harvest tails at scale. A few were even caught releasing rats back into the sewer system just to restock the city’s rat population.

The program backfired spectacularly. Instead of reducing the rat problem, the bounty had created an industry around it.

Eventually, the French shut it down. But the damage had already been done — to public health, to city morale, and to the illusion of control.

We laugh now, but only because it’s familiar.

It’s the same pattern that plays out any time short-term thinking overrides long-term outcomes. The French wanted to solve a crisis quickly — and they paid for results that looked good, instead of outcomes that actually were.

You see it all the time in finance.

A person dips into their 401(k) to handle a temporary emergency, avoiding short-term discomfort — but triggering taxes and penalties that ripple for years.

Another takes out a longer auto loan to lower their monthly payment — even though they’ll pay thousands more in interest and may still owe money when it’s time to replace the car.

We trade long-term health for short-term relief all the time.
And just like the French, we often don’t realize the full cost until much later.

It’s not because we’re reckless. It’s because short-term rewards are louder. They show up in lower stress, smaller bills, or faster wins. Meanwhile, long-term consequences are quiet — until they aren’t.

That’s what makes the Hanoi Rat Bounty such a perfect metaphor. It wasn’t just a mistake in policy — it was a warning about human behavior:

When we’re under pressure, we reach for fast fixes.
But sometimes, the fastest fix is the one that makes the problem permanent.

So the next time you’re faced with a money decision that offers instant gratification — a big tax refund today, a smaller payment this month, or a temporary sense of control — pause and ask yourself:

What am I solving for?
And what might I be trading away to get it?

Because incentives work. They always do.
The only question is whether the benefit is real — or just the tail of something that will keep coming back.