It seems to me that it would be a lot easier for that market concentration to revert to the historical mean without catastrophe, than for P/E ratios to revert to the historical mean without catastrophe.
(I think a reasonable argument can be made that P/E ratios today should be higher than the historical mean, or rather that they should have trended up over time, based on fundamental changes in how companies compensate their shareholders.)
(I think a reasonable argument can be made that P/E ratios today should be higher than the historical mean, or rather that they should have trended up over time, based on fundamental changes in how companies compensate their shareholders.)