This is Hidden Brain. I'm Shankar Vedantam. A few years after the Communist Revolution brought Mao Zedong to power,

China's leader ordered his people to exterminate four pests. Rats, flies, mosquitoes, and sparrows. The birds were eating China's grain.

Chairman Mao had recently collectivized agriculture and he wanted to kill off the birds

consuming his country's food.

During the Great Sparrow campaign, as the effort was called, millions of birds were killed.

People shot sparrows or banged on pots and pans until the birds fell to the ground in exhaustion. But the eradication of the sparrows produced an

unintended consequence. Insect population soared because one of their natural predators had been eliminated.

Locusts swept across China's fields, decimating crops, and contributing to a great famine.

Official figures put the death toll at 15 million people.

Unofficial numbers were 2 to 5 times higher.

While the scale of the disaster was unimaginable,

China is hardly alone when it comes to wrong-headed policies. From nations and

governments to companies and families humans regularly fail to foresee how

initiatives can backfire.

This week we continue our series Success 2.0 with a look at one of the principal sources

of failure in our lives,

unintended consequences.

How to expect the unexpected when we plan for the future

this week on Hidden Brain. Much of life is about getting others to behave in the way we want. We come up with carrots and

sticks to persuade children to do their homework, prompt partners to pick up their socks, and motivate coworkers to do their best.

But often these inducements are ineffective.

Sometimes they even backfire. Urig-Nizi is an economist at the University of California, San Diego.

...