Open Access: Self-Selected, Mandated & Random; Answers & Questions

Davis et al need to do with their randomization methodology what we have done with our mandating methodology, namely, to demonstrate the presence of a self-selected OA Advantage in the same journals and years. Then they can compare that with randomized OA in those same journals and years, and if there is a significant OA Advantage for self-selected OA and no OA Advantage for randomized OA then they will have evidence that -- contrary to our findings -- some or all of the OA Advantage is indeed just a side-effect of self-selection. Otherwise, all they have shown is that with their journals, sample size and time-span, there is no detectable OA Advantage at all.