One can easily see the trap of having epiphenomena fuel action, then justify it retrospectively.
Clive Granger suggests a method to dig out epiphenomena in the cultural discourse and consciousness by looking at the sequence of events and checking out whether one always precedes the other. Also to study differences, that is changes in A and B, not just levels of A and B.
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An epiphenomenon (plural - epiphenomena) is a secondary phenomenon that occurs alongside or in parallel to a primary phenomenon
In medicine, an epiphenomenon is a secondary symptom seemingly unrelated to the original disease or disorder. For example, having an increased risk of breast cancer concurrent with taking an antibiotic is an epiphenomenon. It is not the antibiotic that is causing the increased risk, but the increased inflammation associated with bacterial infection.
In the more general use of the word a causal relationship between the phenomena is implied: the epiphenomenon is a consequence of the primary phenomenon; however, in medicine this relationship is typically not implied: an epiphenomenon may occur independently, and is merely called an epiphenomenon because it is not the primary phenomenon under study. (A side-effect is a specific kind of epiphenomenon that does occur as a direct consequence
http://en.wikipedia....i/Epiphenomenon
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Sir Clive William John Granger /ˈɡreɪndʒər/ (September 4, 1934 – May 27, 2009) was a British economist, who taught in Britain at the University of Nottingham and in the United States at the University of California, San Diego. In 2003, Granger was awarded the Nobel Memorial Prize in Economic Sciences, in recognition that he and his co-winner, Robert F. Engle, had made discoveries in the analysis of time series data that had changed fundamentally the way in which economists analyse financial and macroeconomic data
http://en.wikipedia....i/Clive_Granger