A scheme in Northern Ireland (colloquially known as "Cash for Ash") was set up where heating properties using renewable fuels (mainly biomass) was subsidised, only the subsidy was priced higher than the cost for fuel causing people to heat empty properties just to claim the subsidy. The whole thing cost almost half a billion pounds.

There have been huge allegations of fraud and it even brought down NI's power-sharing executive (~ the regional government) in 2017.

https://en.wikipedia.org/wiki/Renewable_Heat_Incentive_scand...

There's an initiative in Guatemala where land owners are paid an amount of money every year for each acre of their land that they reforest.

Naturally, land owners immediately started clear-cutting virgin rainforest, selling the lumber, and then collecting a payout from the government for planting pine trees that they'll raise for 10 years before they'll cut them down for lumber too.

Sounds like another example of the cobra effect: https://en.m.wikipedia.org/wiki/Cobra_effect

That's a really interesting effect! Thank you for making me aware of it! However it should be noted that the reason it backfired, was because people exploited a weakness in the system, so to speak. It could even be that they did something illegal and fraudulent, since the bounties were obviously for animals that weren't bred in captivity, and for wild animals that were properly killed so they wouldn't be able to procreate. Thus the question remains on whether the measures had effective ways of dealing with such fraud, or whether that would make the whole thing more expensive than other measures.