Unintended consequences

In the <a href="/facts/Social_sciences/hAbm1xtD">social sciences</a>, unintended consequences (sometimes unanticipated consequences or unforeseen consequences, more colloquially called knock-on effects) are outcomes of a purposeful action that are not intended or foreseen. The term was popularized in the 20th century by American <a href="/facts/Sociologist/d2Fd0N87">sociologist</a> <a href="/facts/Robert_K._Merton/9mFwght8">Robert K. Merton</a>.
Unintended consequences can be grouped into three types:

<ul><li>Unexpected benefit: A positive unexpected benefit (also referred to as <a href="/facts/Luck/cpJJMJsF">luck</a>, <a href="/facts/Serendipity/pvcf95kQ">serendipity</a>, or a windfall).</li>
<li>Unexpected drawback: An unexpected detriment occurring in addition to the desired effect of the policy (e.g., while <a href="/facts/Irrigation/RWX5PEgK">irrigation</a> schemes provide people with water for agriculture, they can increase <a href="/facts/Waterborne_diseases/pxM3dqM4">waterborne diseases</a> that have devastating health effects, such as <a href="/facts/Schistosomiasis/qXtvvvUo">schistosomiasis</a>).</li>
<li>Perverse result: A perverse effect contrary to what was originally intended (when an intended solution makes a problem worse).</li></ul>

Unintended consequences open-in-new

Unintended consequences