If you are looking for clues that explain human behavior, consider the effect of incentives.
In a possibly apocryphal story from India under British colonial rule, it seems that the city of Delhi had a problem with an overabundance of cobras. To control the population, the government offered a big bounty for every dead cobra. And it worked marvelously. Huge numbers of cobras were redeemed for the bounty.
But in short order, a surprising thing happened. The cobra problem got worse.
It turned out that people, motivated by the increased value of cobras, began breeding cobras. Cobra farms boomed and the number of cobras increased.
This was the unintended effect of creating an incentive for more cobras.
Good intentions can create unexpected incentives.
A more recent example comes from Mexico City, where the government has tried since 1989 to reduce pollution and traffic congestion by banning some cars from the road one day a week, based on license numbers.
Although the program has been expanded to include a no-drive policy for Saturday, virtually every study shows that the program has had no discernible effect on air quality. City officials hoped that drivers would take public transportation on no-drive days and reduce traffic which also did not seem to happen, according to a 2017 paper published in Nature.
What actually happened? The number of registered vehicles showed a steady increase through the 2000s, according to Nature. In addition, the market for Uber and Lyft increased in the city, which already has an abundant fleet of taxis.
