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The Law of Unintended Consequences

I've spent half a century (yikes) writing for radio and print—mostly print. I hope to be still tapping the keys as I take my last breath.

Many laws and actions are taken with the purest of motives in mind, but then they run into the 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. While some planners are the architects of their own collapses.

The Invisible Hand

The British philosopher and economist Adam Smith recognized the potential for 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 of a positive outcome that was unforeseen. More common is the negative upshot.

The New Delhi Cobra Round-up

The Indian cobra can deliver enough venom in its bite to kill a human through cardiac arrest and/or respiratory failure. So, when the population of these deadly reptiles began growing in New Delhi the colonial British government decided to do something about it. A bounty was put on the head of cobras.

As a United Nations University article notes, “The bounty was generous enough that many people took up cobra hunting, which led exactly to the desired outcome: The cobra population decreased. And that’s where things get interesting.”

The bounty awakened the entrepreneurial spirit in some Indians who started breeding cobras that could be turned in for the cash reward. When the authorities caught on to what was going on they cancelled the bounty.

Breeders now had worthless snakes on their hands, so they set them free. New Delhi soon had more cobras in the streets than when the eradication program started.

This has become known in economics as The Cobra Effect. It makes an appearance with disconcerting frequency.

The Streisand Effect

In 2003, aerial photographer Kenneth Adelman was engaged in a project to create a photographic record of the entire coastline of California. During the course of the venture he snapped an image of Barbra Streisand’s Malibu home. Cue the law of unintended consequences.

Barbra Streisand's Malibu home.

Barbra Streisand's Malibu home.

The singer sued to have the image taken down on the grounds that it invaded her privacy. Prior to the lawsuit, only a handful of people had viewed the image. After the spat became public, 420,000 people clicked onto the photo in a month, causing the very thing that Ms. Streisand was trying to prevent. She lost the lawsuit, and gave her name to what is now known as “The Streisand Effect. It crops up regularly.

Read More From Owlcation

  • In 2017, the government of South Africa said it was going to ban a book that chronicled the corruption of President Jacob Zuma. The President’s Keepers then shot off the shelves of bookstores, requiring many reprints.
  • California Republican Congressman Devin Nunes filed a defamation lawsuit against Twitter in March 2019. He claimed $250 million in damages from a user who operated a parody of Nunes’s Twitter account. The spoof account jumped from 1,200 followers to 600,000.
  • Scottish primary school student Martha Payne began a blog about the meals served at her school; her comments were not complementary. On June 14, 2012, Martha was told she could no longer post images of school meals on her blog. The result was millions of hits and the young student became a media sensation. The ban was lifted, but the local council came out of the attempted censorship looking like idiots.
One of Martha Payne's "lunches."

One of Martha Payne's "lunches."

Causes of Unintended Consequences

The American sociologist Robert K. Merton wrote an influential article that codified the concept of unforeseen results coming from social planning. In The Unanticipated Consequences of Purposive Social Action (1936) Merton identified five ways in which plans become unglued:

  1. Ignorance―It’s not possible to anticipate every outcome;
  2. Errors―Failed analysis of how human behaviour changes;
  3. Immediate interest―Short-term thinking in dealing with a long-term problem, which leads to pretending negative outcomes don’t exist;
  4. Basic values―Merton wrote that the Protestant value of hard work and self-denial “paradoxically leads to its own decline through the accumulation of wealth and possessions;” and,
  5. Self-defeating prophecy―Sometimes, out of fear, people develop a solution to a problem that does not yet exist and never shows up.

Psychologist Stuart Vyse has added “groupthink” as a sixth cause; the urge to conform causes people to place harmonious connection above critical thinking.

A confluence of several of those failures led to perhaps the worst example of unintended consequences in American history―prohibition.

Bonus Factoids

  • When countries initiate seat belt and air bag regulations injuries to pedestrians rise because drivers feel safer and behave less cautiously;
  • California introduced its Three Strikes law in 1994 creating an automatic life sentence after a third conviction. This made life more dangerous for police officers as criminals with two convictions started shooting cops rather than being arrested;
  • Licensing electricians reduces the number of people competent in electrical repairs. This encourages homeowners to try to fix things themselves, sometimes with disastrous results;
  • In 1989, the oil tanker Exxon Valdez smacked into rocks and caused a massive oil spill in Alaska. Coastal states reacted by placing unlimited liability on oil companies for any future spills. Oil companies responded by tying up their fleets and hiring less responsible carriers with dodgy insurance to transport oil.
  • The loss of the SS Titanic prompted the passage of laws mandating enough lifeboats aboard ships to accommodate every passenger. The addition of lifeboats to the poorly designed SS Eastland made the vessel unstable. She rolled over in the Chicago River, killing 844 people.


  • “Systems Thinking and the Cobra Effect.” Barry Newell and Christopher Doll, United Nations University, September 16, 2015.
  • “Definition of ‘Invisible Hand’ ” The Economic Times, undated.
  • “Unintended Consequences.” Rob Norton, Library of Economics and Liberty, undated.
  • “The Streisand Effect: When Censorship Backfires.” Mario Cacciottolo, BBC News, June 15, 2012.
  • “Five examples of the Law of Unintended Consequences.” Mark J. Perry, American Enterprise Institute, January 12, 2014.
  • “The Cobra Effect: Lessons in Unintended Consequences.” Anthony Davies and James R. Harrigan, Foundation for Economic Education, September 6, 2019.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2020 Rupert Taylor


Rodric Anthony Johnson from Surprise, Arizona on October 29, 2020:

I love your informative articles.

Rupert Taylor (author) from Waterloo, Ontario, Canada on October 28, 2020:

It's weird John, because I started out intending to write a completely different article.

John Hansen from Gondwana Land on October 28, 2020:

What an interesting article, Rupert. There certainly be many unintended consequences to actions. The cobras in New Delhi was an excellent example and the Streisand effect. Thank you for this entertaining and educational read.

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