[humodz]

There's the Cobra Effect popularized by Freakonomics

Too many cobras > bounty for slain cobras > people start breeding them for the bounty > law is revoked > people release their cobras > even more cobras around

[dredmorbius]

The Freakonomics coverage was based on the book The Great Hanoi Rat Hunt by Michael G. Vann.

He was recently interviewed about that book on the New Books Network:

<https://newbooksnetwork.com/michael-g-vann-the-great-hanoi-r...>

Audio: <https://traffic.megaphone.fm/LIT1560680456.mp3> (mp3)

(Episode begins at 1:30.)

Among the interesting revelations: the rat problem was concentrated in the French Quarter of Hanoi, as that's where the sewerage system was developed. What drained away filth also provided an express subway for rats. Which had been brought to Vietnam by steamship-powered trade, for what it's worth.

(That's only a few minutes into the interview. The whole episode is great listening, and includes a few details on the Freakonomics experience.)

[dredmorbius]

Correction: Both the Freakonomics coverage and the book named above were based on an earlier paper, though both that and the book were by Vann.

[cortesoft]

The Cobra Effect is an example of a Perverse Incentive, which is where an attempt to incentivize a behavior ends up incentivizing the opposite: https://en.wikipedia.org/wiki/Perverse_incentive

I think most of the examples fit this, but a few don't.

[smusamashah]

This also sounds similar to Goodhart's Law which states that “when a measure becomes a target, it ceases to be a good measure.”

https://en.m.wikipedia.org/wiki/Goodhart%27s_law