Radio 4's brilliant More Or Less programme included a great story about cobras and it is a great example of unintended consequences.

The story is that Delhi was over-run with venomous cobras and the colonial government needed to have them culled. India is an amazingly entrepreneurial country full of bright, energetic people looking to earn money. So when the colonial government decided to offer a bounty for each dead snake, citizens realised this was a potential income so they began breading cobras in order to kill them and claim the bounty. Eventually, the government cottoned on and stopped the bounty. What does an entrepreneur with a now useless stock do? They get rid of it. Cobras were released and came back into Dehli. At the end of the project, the overall the number of cobras had gone up.

It's a great story of unintended consequences of a decision that seems very sensible at the start. For a business example, the Wells Fargo account fraud scandal is a dire warning. Wells Fargo employees were incentivised to cross sell to customers, for example, a bank account customer might be cross sold a credit card or a savings account. Branch staff were pressurised and incentivised to meet targets for cross selling. Sales did indeed go up but sadly it was fraudulent, with employees opening up accounts and credit cards without customer agreement. In the ensuing scandal, over 5,000 staff lost their jobs and Wells Fargo was heavily fined.

Both stories are great warnings about unintended consequences arising from decisions and that what get's rewarded gets repeated.