Seems like current high P/E ratios could be related to having just gone through an extended period of very low interest rates. When rates are low, some (many?)

Seems like current high P/E ratios could be related to having just gone through an extended period of very low interest rates. When rates are low, some (many?) investors may decide that the stock market looks better than lending (either directly or indirectly). And then that can be a self-reinforcing cycle as well--more money going into stock markets == stocks perform better == stocks look like an even better investment.