The question What are the benefits of learning radicals? was closed in October 2014 as "primarily opinion-based". This is a strange close reason for this question, since benefits can be established in an objective manner, for example through studies that compare people who learn radicals and people who don't learn radicals and testing for any differences in retention of kanji.
I have rephrased the question a bit so it now asks about studies on this topic. Is this sufficient to have the question reopened. (I also asked about this in the chat room, but that did not help.)