Set forth below is the text of an answer that I recently posted to a question (“When Will the Stock Market Crash Again?”) at the Quora site:
There are two popular schools of thought re market timing. One is that it is impossible to time the market effectively and a waste of effort to try. The other is that knowing when crashes are coming is so valuable that you just have to give the objective of predicting them your best possible shot.
I hold a third view, a view which I believe is strongly supported by the research of Yale University Economics Professor Robert Shiller and research (including one paper that I did most of the work on myself!) done over the past 32 years (and largely ignored so far!). That view holds that short-term timing (predicting when crashes will come with precision) really is impossible but that predicting in a general way when they will come (long-term timing) is highly doable and absolutely required for those seeking to hold any realistic hope of long-term investing success.
Shiller’s model uses valuations to make long-term predictions. Once prices go insanely high, we ALWAYS experience a wipe-out. There has never in 140 years of stock market history ever been an exception. But we CANNOT say with precision when the wipeout will come, only that it is on its way.
There is a wipe-out on its way today, according to the Shiller model. Thus, I think it makes sense to go with a low stock allocation today.
We may see stock prices double over the next year. If we see that, there are people who will complain that I was “wrong” in my advice.
I don’t see it that way. The way I look at it is that the RISK of a crash is high this year. Thus, we all should be going with low stock allocations. It doesn’t matter whether stocks actually crash this year or not. The risk is there. That’s what matters.
Those who stay in stocks and enjoy another run-up in prices will NOT get to keep the money. They will lose all those gains plus a lot more in the crash that will follow next year or the year after that. So what good do those gains do them? I invest for the long-term. I want gains I can keep. Investors have never earned permanent gains from stock purchases made when stock were selling at the sort of prices at which they are selling today.
The losses you will see if stocks continue to perform in the future anything at all as they have always performed in the past will be devastating. It is hard for people to get their heads around how much one wipeout in a lifetime can hold you back. You lose not only the dollar value taken from your portfolio, you also lose decades of compounding returns on those dollars. Stay heavily in stocks at a time like today and you could easily set your retirement back 10 years, according to the last 30 years of academic research.
The “experts” won’t tell you this. Most of the “experts” in this field make money only when people buy stocks. So they are compromised. You need to become personally familiar with what the academic research really says, not just what the people quoted as experts in this field SAY that it says. These are very, very, very different things, in my experience. The conventional wisdom in this field is dangerous stuff.