I’ve posted Entry #199 to my weekly Valuation-Informed Indexing column at the Value Walk site. it’s called Investing Strategies That Ignore the Effects of Stock Crashes Cannot Work.
Juicy Excerpt: You really only need to know one thing about stock market history to know that the market is not efficient. Prices crash from time to time. If prices were determined by economic realities, there would be ups and downs in prices. But there would never be crashes. The market lost over $9 trillion in value in the 2008 crash. There is zero chance that informed investors had in late 2008 taken note of changes in the economic realities serious enough to justify that sort of change. The market crashed because market prices are determined primarily by shifts in investor emotions and one of the characteristics of emotions is that they change suddenly and harshly.
Emotions are not rooted in logic. So they can do just about any crazy thing. It is critical that those studying stock investing come to a better appreciation of this seemingly obvious implication of Shiller’s “revolutionary” (his word) finding. When I tell people that the numbers show that it was the relentless promotion of Buy-and-Hold strategies that served as the primary cause of the economic crisis, they find it a hard reality to take in.
It doesn’t make sense! Surely investors would not let prices get so out of hand as to cause $12 trillion of consumer buying power to disappear from the economy as prices worked their way back to fair-value levels. No, it doesn’t make sense. But bull markets aren’t supposed to make sense. They are an emotional phenomenon, not a rational one. What would make sense is for the P/E10 always to remain at 15, the fair-value P/E10 number. Higher P/E10 values signify the presence of unhealthy levels of investor emotion and we need to pay attention to those readings if we are to invest effectively for the long-term and to avoid the sorts of economic crises that have followed every secular bull market experienced over the 140 years of stock market history available to us today.
So long as stock market prices are determined by emotional phenomena, we are going to see terrifying price crashes and the terrifying economic crises that inevitably follow from them. The other and more positive way of stating it is that, now that we are aware that market prices are determined by emotional phenomena, we are empowered to avoid crashes and economic crises by educating investors as to how they need to respond to bull-market prices to win higher lifetime returns and earlier retirements for themselves.