In Part 1 we looked at a personal example of unintended consequences and examples of consequences that create new problems. In this part we turn to unexpected benefits, the causes of unintended consequences and tips on avoiding or anticipating them. The notes at the end of this entry cover both parts, so the note numbers below continue from Part 1.
Lest we think that all unintended consequences are bad, sometimes they can be quite beneficial.
- The medieval policy of setting up large hunting reserves for the nobility has preserved green space, often as parks, throughout England and other places in Europe. Likewise the creation of "no-man's lands" during the Cold War, in places such as the border between Eastern and Western Europe, and the Korean Demilitarized Zone, has led to large natural habitats.[j-l]
- The sinking of ships in shallow waters during wartime has created many artificial coral reefs, which can be scientifically valuable and have become an attraction for recreational divers.[m-q]
- In medicine, most drugs have unintended consequences ('side effects') associated with their use. However, some are beneficial. For instance, aspirin, a pain reliever, is also an anticoagulant that can help prevent heart attacks and reduce the severity and damage from thrombotic strokes.The existence of beneficial side effects also leads to off-label use—prescription or use of a drug for an unlicensed purpose. [r]
- Showing the importance of a long-range view, Stephen Wagner and Lee Dirrmar wrote in the Harvard Business Review in 2006 about the impact of the Sarbanes-Oxley Act of 2002. Its requirements for financial record keeping were considered onerous by many,
“Yet in the course of providing compliance advice to executives, we discovered a small subset who approached the new law with something like gratitude. For years, and especially when financial reporting had become fast and loose and criminal conduct entrenched at places like WorldCom and Enron, these executives had secretly wished that some of the resources absorbed by their companies’ profit centers could have been diverted to improving financial management processes and capabilities. They were thinking not only of protecting stakeholders and shielding their companies from lawsuits but of developing better information about company operations in order to avoid making bad decisions.” 
The causes and prevention of unintended consequences
These examples, and myriad others, illustrate what economists and social scientists have attempted to define. Rob Norton provides a good summary in an article in The Concise Encyclopedia of Economics.  The high points:
- Adam Smith‘s “invisible hand” described the self-interest of one (a butcher or baker) serving the public interest (dinner at your house).|
- In 1692 the English philosopher John Locke spoke against a bill in parliament designed to cut the maximum permissible interest rate from 6 percent to 4 percent, Locke argued that attempts to circumvent the law would result in “less available credit and a redistribution of income away from ‘widows, orphans and all those who have their estates in money’.” This, says Norton, “illuminates the perverse unanticipated effects of legislation and regulation.”
rnalist Fredéric Bastiat distinguished between the “seen” and “unseen.” In a famous essay “What is Seen and What is Not Seen” Bastiat wrote:
“There is only one difference between a bad economist and a good one: the bad economist confines himself to the visible effect; the good economist takes into account both the effect that can be seen and those effects that must be foreseen.”(s)
- The first and most complete analysis of the concept of unintended consequences was done in 1936 by the American sociologist Robert K. Merton. In an influential article titled “The Unanticipated Consequences of Purposive Social Action,” Merton identified five sources of unanticipated consequences. [The list that follows comes from a Wikipedia article that summarizes Norton’s narrative – If you are interested, Norton goes on to discuss much more about critiques of the law of unintended consequences found in government and public life. Follow the link in the Notes below.]
- Ignorance, making it impossible to anticipate everything, thereby leading to incomplete analysis
- Errors in analysis of the problem or following habits that worked in the past but may not apply to the current situation
- Immediate interests overriding long-term interests
- Basic values which may require or prohibit certain actions even if the long-term result might be unfavorable (these long-term consequences may eventually cause changes in basic values)
- Self-defeating prophecy, or, the fear of some consequence which drives people to find solutions before the problem occurs, thus the non-occurrence of the problem is not anticipated 
I like the list offered by the contributor to the Wikipedia article on unintended consequences
Possible causes of unintended consequences include the world's inherent complexity (parts of a system responding to changes in the environment), perverse incentives, human stupidity, self-deception, failure to account for human nature, or other cognitive or emotional biases. As a sub-component of complexity (in the scientific sense), the chaotic nature of the universe—and especially its quality of having small, apparently insignificant changes with far-reaching effects (e.g., the butterfly effect)—applies. 
The role of human nature is critical. In fact, it could be said that the first reference to unintended consequences is found in the opening chapters of the book of Genesis with the story of Adam and Eve in the Garden of Eden.
Regardless of the level of wisdom and foresight, some consequences cannot be anticipated and are totally unexpected. Too often, however, they are a result of selfish ambition, political agendas, arrogance, and other human frailties. We can also be caught be exuberance and optimism—good qualities—but ones that need to be kept in perspective when considering the consequences of our planning and decision-making.
How to avoid or anticipate unintended consequences
Here are a few tips. Your own experience may suggest others. My own perspective is that of smaller businesses and organizations that do not have a permanent legal staff (though this can introduce its own pitfalls).
- Respect and learn from history. When planning a new action, study similar situations in the past. Where there were damaging consequences, how could they be avoided now? When there were unexpected benefits, what circumstances allowed them to surface and can you help create such an environment?
- Understand the systemic impact and potential perverse response. When an action affects a larger system (environment, economy, a company, an organization, a family), seriously consider how an even seemingly minor tweak can result in a much larger negative effect. Even more, consider the effect of people attempting to circumvent the action and the deleterious effect than may have on those who should benefit from your action. Or, in cases of environmental and very large systems, are their inherent balances that will be disrupted (immediately or further down the road), that will ultimately produce destructive rather than constructive results?
- Allow sufficient time to process the planned action. Rushing into a situation (or letting the decision-process go on endlessly) can be an invitation to disaster. Use time wisely to thoroughly investigate and bring disparate positions together.
- Consider obstacles and restraints (regulations, legal, financial, personnel) that may create “chinks in the armor” through which unintended consequences could emerge.
- Consider worst case scenarios. Surround your planning with optimism but center it on reality. Bring enough views to the discussion to fully consider the worst that could happen, whether it can be dealt with, or how it should change the parameters of the proposed action. Good leadership calls for the presence of a “devil’s advocate” to test the wisdom of the intended action—whether that is represented by a person or a group, and whether it is sufficient to use internal resources or bring in external expertise. This is especially important when everyone is onboard early, there have been few if any dissenting voices, and it seems there could be no major problems (an indication of "group think")..
- Prepare a path for response. Rather than simply setting something in motion and watching bad things happen, there should be mechanisms available to monitor the results of an action and take corrective action when necessary. Like other parts of the process, this response should be thoughtful and given enough time to make a useful correction rather than exacerbating the situation by knee-jerk reactions that only invite even more unintended consequences!
- Wikipedia article on unintended consequences - en.wikipedia.org/wiki/Unintended_consequences
- What are the best examples of the law of unintended consequences in action? www.quora.com/What-are-the-best-examples-of-the-law-of-unintended-consequences-in-action
- 30 Unintended Consequences of Global Events that Shaped Where Humanity is Today - thoughtcatalog.com/michael-koh/2014/01/30-unintended-consequences-of-global-events-that-shaped-where-humanity-is-today/
- The Unexpected Benefits of Sarbanes-Oxley by Stephen Wagner and Lee Dittmar, Harvard Business Review, April 2006 - hbr.org/2006/04/the-unexpected-benefits-of-sarbanes-oxley
- Unintended Consequences, by Rob Norton in The Concise Encyclopedia of Economics - www.econlib.org/library/Enc/UnintendedConsequences.html
Secondary Sources (notes within primary sources – links have been checked and left intact, but marked “invalid” if no longer working)
- "Our innate ability to think of new ways to use energy" Professor Tadj Oreszczyn. Summer 2009 edition of ‘palette’, UCL’s journal of sustainable cities.
- Bin Laden comes home to roost at the Wayback Machine (archived December 2, 1998)
- "Blowback – 96.05". Theatlantic.com. Retrieved 2012-11-21.
- Peter Beaumont, foreign affairs editor. "Why 'blowback' is the hidden danger of war | World news". The Observer. Retrieved 2012-11-21.
- Dikotter, Frank (2010). Mao's Great Famine. New York: Walker & Co. p. 188.
- Moote, Lloyd and Dorothy: The Great Plague: the Story of London's most Deadly Year, Baltimore, 2004. p. 115.
- Likens, G. E.; Wright, R. F.; Galloway, J. N.; Butler, T. J. (1979). "Acid rain". Sci. Amer. 241 (4): 43–51. doi: dx.doi.org/10.1038%2Fscientificamerican1079-43 [invalid link]
- Likens, G. E. (1984). "Acid rain: the smokestack is the "smoking gun". Garden 8(4): 12–18.
- Joyce, Christopher. "How The Smokey Bear Effect Led To Raging Wildfires" .npr.org. Retrieved 27 August 2012.
- "From Iron Curtain to Green Belt: How new life came to the death strip". London: Independent.co.uk. 2009-05-17. Retrieved 2010-05-07.
- Kate Connolly (2009-07-04). "From Iron Curtain to Green Belt". London: Guardian. Retrieved 2010-05-07. www.guardian.co.uk/travel/2009/jul/04/germany-green-line-iron-curtain
- "European Green Belt". European Green Belt. Retrieved 2010-05-07. europeangreenbelt.org/001.route_ce.html [invalid link]
- "Maryland Artificial Reef Initiative Celebrates 1 Year Anniversary". Dnr.maryland.gov. 2008-02-07. Retrieved 2010-05-07. www.dnr.maryland.gov/dnrnews/pressrelease2008/020708a.html [invalid link]
- "Sinking ships will boost tourism, group says – News – msnbc.com". MSNBC. 2007-05-25. Retrieved 2010-05-07. www.msnbc.msn.com/id/18853363/
- "Life after death on the ocean floor – The National Newspaper". Thenational.ae. 2009-09-21. Retrieved 2010-05-07. www.thenational.ae/apps/pbcs.dll/article?AID=/20090921/NATIONAL/709209873/1042/FOREIGN
- "Sea Life Flourishing On Vandenberg Wreck Off Keys". cbs4.com. 2009-10-15. Retrieved 2010-05-07. cbs4.com/local/vandenberg.fish.key.2.1250653.html [invalid link]
- "CDNN :: Diver Wants to Sink Old Navy Ships off California Coast". Cdnn.info. 2006-12-27. Retrieved 2010-05-07. www.cdnn.info/news/industry/i061227.html
- "BBC 15 February 2001, Aspirin heart warning". BBC News. 2001-02-15. Retrieved 2010-05-07. news.bbc.co.uk/1/hi/health/1168850.stm
- Bastiat, Frédéric. “What Is Seen and What Is Not Seen.” Online at: www.econlib.org/library/Bastiat/basEss1.html.
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