Using Bayes’ Theorem to test Emerging Democratic Majority
http://www.realclearpolitics.com/articles/2014/10/28/putting_the_emerging_democratic_majority_theory_to_the_test_124460.html
Using Bayes’ Theorem to test Emerging Democratic Majority
A recent article written by Sean Trende, the Senior Elections Analyst at RealClearPolitics and a political analyst specializing in American elections analysis, dives into putting the ‘Emerging Democratic Majority’ (EDM) Theory to test. The EDM Theory states that “demographic and sociological changes are driving the country toward a progressive majority”. In the article, Trende uses Bayes’ Theorem to look at whether or not EDM is true, based on EDM skeptics and progressors.
In the article, Trende concedes that the chances of a false negative are low which means that P(E|H) will be set pretty high (0.9) for the sake of arguments because we are not given concrete numbers in this case. This concession means that the probability of seeing the evidence of Emerging Democratic Majority that EDM theorists predict is very high if we are in fact in an Emerging Democratic Majority.
Yet, Trende also goes on to say in the article that although skeptics and theorists alike will use Bayes’ Theorem, it is hard to actually predict whether or not EDM will occur, or if the circadian rhythm of Congress is, in fact, predictable, even with all of the analytic tools and theorems available to us today. In Trende’s mind, there is still an uncertainty whether or not the evidence for EDM will actually predict Emerging Democratic Majority in the future.