{"id":837,"date":"2014-02-21T11:48:13","date_gmt":"2014-02-21T16:48:13","guid":{"rendered":"http:\/\/blog.richmond.edu\/physicsbunn\/?p=837"},"modified":"2014-02-21T11:48:13","modified_gmt":"2014-02-21T16:48:13","slug":"correlation-is-correlated-with-causation","status":"publish","type":"post","link":"https:\/\/blog.richmond.edu\/physicsbunn\/2014\/02\/21\/correlation-is-correlated-with-causation\/","title":{"rendered":"Correlation is correlated with causation"},"content":{"rendered":"<p>My old friend Allen Downey has a <a href=\"http:\/\/allendowney.blogspot.com\/2014\/02\/correlation-is-evidence-of-causation.html\">thoroughly sensible post<\/a> about correlation and causation.<\/p>\n<blockquote><p>It is true that correlation doesn&#8217;t imply causation in the mathematical sense of &#8220;imply;&#8221; that is, finding a correlation between A and B does not prove that A causes B. However, it does provide evidence that A causes B. It also provides evidence that B causes A, and if there is a hypothetical C that might cause A and B, the correlation is evidence for that hypothesis, too.<\/p><\/blockquote>\n<p>If you don&#8217;t understand what he means by this, or if you don&#8217;t believe it, read the whole thing.<\/p>\n<p>I do think he&#8217;s guilty of a bit of rhetorical excess when he says that &#8220;the usual mantra, &#8216;Correlation does not imply causation,&#8217; is true only in a trivial sense.&#8221; I think that the mantra means something quite specific and valid, namely something like &#8220;<em>correlation does not provide evidence for causation that&#8217;s as strong as you seem to think<\/em>.&#8221; One often sees descriptions of measured correlations that imply that the correlation supports the hypothesis of causation to the exclusion of all others, and when that&#8217;s wrong it&#8217;s convenient to have a compact way of saying so.<\/p>\n<p>But that&#8217;s a small quibble, which gets even smaller if I include the next phrase in that quote from Allen,<\/p>\n<blockquote><p>The point I was trying to make (and will elaborate here) is that the usual mantra, &#8220;Correlation does not imply causation,&#8221; is true only in a trivial sense, <em>so we need to think about it more carefully<\/em>\u00a0[emphasis added].<\/p><\/blockquote>\n<p>I couldn&#8217;t agree more, and everything Allen goes on to say after this is 100% correct.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>My old friend Allen Downey has a thoroughly sensible post about correlation and causation. It is true that correlation doesn&#8217;t imply causation in the mathematical sense of &#8220;imply;&#8221; that is, finding a correlation between A and B does not prove that A causes B. However, it does provide evidence that A causes B. It also &hellip; <a href=\"https:\/\/blog.richmond.edu\/physicsbunn\/2014\/02\/21\/correlation-is-correlated-with-causation\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Correlation is correlated with causation<\/span><\/a><\/p>\n","protected":false},"author":12,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-837","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/blog.richmond.edu\/physicsbunn\/wp-json\/wp\/v2\/posts\/837","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.richmond.edu\/physicsbunn\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.richmond.edu\/physicsbunn\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.richmond.edu\/physicsbunn\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.richmond.edu\/physicsbunn\/wp-json\/wp\/v2\/comments?post=837"}],"version-history":[{"count":0,"href":"https:\/\/blog.richmond.edu\/physicsbunn\/wp-json\/wp\/v2\/posts\/837\/revisions"}],"wp:attachment":[{"href":"https:\/\/blog.richmond.edu\/physicsbunn\/wp-json\/wp\/v2\/media?parent=837"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.richmond.edu\/physicsbunn\/wp-json\/wp\/v2\/categories?post=837"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.richmond.edu\/physicsbunn\/wp-json\/wp\/v2\/tags?post=837"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}