How Unintended Consequences Cause Havoc

It’s next to impossible to anticipate the full impact of a social policy in complex systems that interact with one another

Many laws and actions are taken with the purest of motives in mind, but then they run into that most unreliable of animals―humans.

Through cunning, inventiveness, and, sometimes, sheer stupidity, people have an amazing ability to make the most carefully laid plans fail.

The Invisible Hand

The British philosopher and economist Adam Smith recognized the potential of unintended consequences. In his 1776 book The Wealth of Nations he wrote that each person works to improve his own self interest and “is led by an invisible hand to promote an end which was no part of his intention.”

That end result, wrote Smith, is benefits to the public interest: “It is not from the benevolence of the butcher, or the baker, that we expect our dinner, but from regard to their own self interest.”

This is an example a positive outcome that was unforeseen. More common is the negative upshot.