Unintended consequences

Unintended consequences are the surprising results of an action or decision.

When an outcome is not anticipated or foreseen, the situation at the end of a process may be different from what was intended.  In other words, purposeful action may create consequences which are: 
 Not intended (unintended)
 Not expected (unanticipated) 
 Not predicted (unforeseen)

This concept is one of the building blocks of economics.Norton, Rob.  "Unintended Consequences," The Concise Encyclopedia of Economics; retrieved 2012-6-25.  The term was coined and popularised in the 20th century.Hollander, Jason. "Renowned Columbia Sociologist and National Medal of Science Winner Robert K. Merton Dies at 92," Columbia News (US). February 25, 2003; retrieved 2012-6-25. Its use has expanded into a range of contexts.

History
The idea of unintended consequences dates back at least to the 18th century, when Adam Smith wrote about men who are "led by an invisible hand to promote an end which was no part of his invention".Smith, Adam. (1791).   An Inquiry Into the Nature and Causes of the Wealth of Nations, Vol. 2, p. 273.

American sociologist Robert K. Merton invented the phrase in 1936.Merton, Robert K.  The unanticipated consequences of purposive social action. American Sociological Review, 1, (6), 894–904; retrieved 2012-6-25.

 Types 
There are three types of unintended consequences:
 A positive, unexpected good effect (also described as good luck)
 A negative, unexpected bad effect in addition to what was expected
 A strange, unpredicted effect which is outside the scope or opposite to what was intended

 Causes 
Possible causes of unanticipated consequences include

Ignorance
 In other words, it is impossible to anticipate everything, and this leads to an analysis which is not detailed enough.Merton, pp. 898-901 [PDF 6-9 of 12]; retrieved 2012-6-25.

Error
 In other words, there is an incorrect or mistaken analysis.  For example, error might result from following a process or procedure which worked in the past but which does not work well enough or not at all in a new situation.Merton, p. 901 [PDF 9 of 12]; retrieved 2012-6-25.

 Immediate interest
 In other words, the focus on short-term goals may be viewed as more important than long-term interests.Merton, pp. 901-903 [PDF 9-11 of 12]; retrieved 2012-6-25.

Basic values
 In other words, there may be factors which require or prohibit certain actions regardless of the long-term results.Merton, pp. 903 [PDF 9-11 of 12]; retrieved 2012-6-25.

 Select examples 
There are examples and kinds of unanticipated consequences:

Unexpected and good
Aspirin is a pain reliever.  Among other things, aspirin affects the blood's ability to clot.  An unintended consequence is that aspirin is sometimes good for people with heart problems."Aspirin heart warning," BBC News (UK). 15 February 2001; retrieved 2012-6-25.

 Unexpected and bad 
 Rabbits were introduced in Australia and New Zealand; but without any natural enemies to slow the growth in numbers, there was an unanticipated consequence. There was a problem of too many rabbits in both countries."The State Barrier Fence of Western Australia,"; "Rabbits: Introduction into New Zealand"; retrieved 2012-6-25.

 Unexpected and worse
 In India, the southern provinces had the problem of too many snakes.  The government tried to solve the problem by paying for dead cobras.  This was intended to bring down the number of cobras. Instead, it led to the breeding of cobras.  When the government stopped paying for dead cobras, the snakes were released—and the problem was worse than before the government tried to do something about it.Brickman, Leslie H. (2002). Preparing the 21st Century Church, p. 326.

 Cheaper and easier travel 
Cheaper travel, mostly in the form of air transport, is hugely beneficial to the economy by increasing tourism into a country. It accounts for 30% of the world's trade of services, and 6% of overall exports of goods and services.International tourism receipts surpass US$ 1 trillion in 2011. Press release, UNWTO. 7 May 2012. Retrieved 15 June 2012   It also creates opportunities for employment in the services needed for tourism.

With increased tourism comes a variety of unlooked-for problems, such as increased illegal immigration. Perhaps even more serious is that returning tourists may bring back parasites and diseases which are not usual in the home country. Furthermore, many of these organisms are now resistant to most treatment.Maryn McKenna 2012. Totally resistant TB: earliest cases in Italy. Wired magazine. Retrieved 12 January 2012. 

 Related pages 
 The road to hell is paved with good intentions
 Perverse incentive
 Moral hazard

 References 

Category:Sociology
Category:Economics
Category:Causality
Category:Social sciences terminology