I think there is definitely a relationship between price and earnings, but
[1] I'm not sure that it is as close as many think; and,
[2] Between "P" & "E" I'm not certain which is the tail and which the doggie; and,
[3] I'm not certain that the old saw about PEs always dropping to single digits at the end of a bear market -- at least a bubble-blow-off-bear-market -- is correct. I think it's quite possible that in reality what happens is that PEs drop to a level below that which obtained at the beginning of the bubble.