Shiller PE: Problems Behind the Broken CAPE Tool

Updated on

If something sounds like BS, looks like BS, and smells like BS, there’s a good chance you’re probably eyeball-deep in BS. In the investment world, I encounter a lot of very intelligent analysis, but at the same time I also continually step into piles of investment BS. One of those piles of BS I repeatedly step into is the CAPE ratio (Cyclically Adjusted Price-to-Earnings) created by Robert Shiller. For those who are not familiar with Shiller, he is a Nobel Prize winner in economics who won the award in 2013 for his work on the “empirical analysis of asset prices.” Shiller vaulted into fame in large part due to the timing of his book, Irrational Exuberance, which was published during the 2000 technology market peak. He gained additional street-credibility in the mid-2000s when he spoke about the bubble developing in the real estate markets.

What is the CAPE / Shiller PE ?

Besides being a scapegoat for every bear that has missed the tripling of stock prices in the last five years, the CAPE effectively is a simple 10-year average of the P/E ratio for the S&P 500 index. The logic is simple, like many theories in finance and economics, there often are inherent mean-reverting principles that are accepted as rules-of-thumb. It follows that if the current 10-year CAPE is above the 134-year CAPE average, then stocks are expensive and you should avoid them. On the other hand, if the current CAPE were below the long-term CAPE average, then stocks are cheap and you should buy. Here is a chart of the Shiller PE CAPE:

Shiller-CAPE Shiller PE
Shiller PE

As you can see from the chart above, the current CAPE ratio of 26x is well above the 134-year average of 16x, which according to CAPE disciples makes the stock market very expensive. Or as a recent Business Insider article stated, the Shiller PE / CAPE is “higher than at any point in the 20th century with the exception of the peaks of 1929 and 2000 – you know what happened after those.”

Shiller PE Problems Behind the Broken CAPE Tool

There are many problems with Shiller’s CAPE analysis, but let’s start with the basics by first asking, how useful has this tool actually been over the last, 10, 20, or 30 years? The short answer…not very. For example, if investors followed the implicit recommendation of the CAPE for the periods when Shiller’s model showed stocks as expensive (see above chart 1990 – 2014), they would have missed a more than quintupling (+469% ex-dividends) in the S&P 500 index. Over a shorter timeframe (2009 – 2014) the S&P 500 is up +114% ex-dividends (+190% since March 2009).

Even if you purchased at the worst time at the peak of the stock market in 2000 when the CAPE was 44 (S&P 500 – 1553), an investor would still have earned a total return of about +45% from 2000 – 2014, despite the CAPE still being 63% higher (more expensive) than the 134-year CAPE average of 16.

Shiller PE Peaches for $.25 Post-Bubble?

To illustrate a point, let’s assume you are a peach lover and due to a bubble in peach demand, prices spiked to an elevated level of $2.60 per pound for 9 years, but in year 10 the price plummeted to $.25 per pound today (see chart below). Assuming the 134-year average for peach prices was $1.60 per pound, would you still want to purchase your beloved peaches for the fire sale price of $.25 per pound? Common sense tells you $.25/lb. is a bargain, but if you asked the same question to Robert Shiller, he would say absolutely “NO”! The 10-year Peach Shiller PE CAPE ratio would be $2.37 ([9 yrs X $2.60] + [1 yr X $.25]) #1, but since the 10-year Shiller PE is greater than the LT-Average peach price of $1.60 per pound #2Shiller would say peaches are too expensive, even though you could go to Kroger (KR) and buy a pound of peaches today for $0.25 #3.

Peach Chart Shiller PE
Shiller PE

This complete neglect of current market prices in the calculation of CAPE makes absolutely no sense, but this same dynamic of ignoring current pricing reality is happening today in the stock market. Effectively what’s occurring is the higher P/E ratios experienced over the last 10 years are distorting the Shiller CAPE ratio, thereby masking the true current value of stocks. In other words the current CAPE of 26x vastly exaggerates the pricey-ness of the actual S&P 500 P/E ratio of 16x for 2014 and 14x for 2015.

There are plenty of other holes to poke into CAPE, but the last major component of Shiller’s ratio I want to address is interest rates. Even if you disregard my previous negative arguments against Shiller’s CAPE, should anyone be surprised that the ratio troughed in the early 1980s of 7x when long-term interest rates peaked. If I could earn 18% on a CD with little risk in 1981, not many people should be dumbfounded that demand for risky stocks was paltry. Today, the reverse environment is in place – interest rates are near record lows. It should therefore come as no surprise, that all else equal, a higher P/E (and CAPE) is deserved when interest rates are this low. Nevertheless, this discussion of P/E and CAPE rarely integrates the critical factor of interest rates.

While I have spent a decent amount of time trashing the CAPE /Shiller PE/ -BS ratio, I want to give my pal Bob Shiller a fair shake. I can do this by looking into a mirror and admitting there are periods when the CAPE ratio can actually work. Although the CAPE is effectively useless during long, multi-year upward and downward trending markets (think bubbles & depressions), the CAPE makes perfect sense in sideway, trendless markets (see chart below).

Cycle Chart Shiller PE
Shiller PE

The investing public is always looking for a Holy Grail financial indicator that will magically guide them to riches in both up and down markets. Despite the popularity of Shiller’s CAPE ratio, regrettably no one perfect indicator exists. So before you jump on the bandwagon and chase the hot indicator du jour, make sure to look down and make sure you haven’t stepped in any Shiller CAPE-BS.

www.Sidoxia.com

Wade W. Slome, CFA, CFP®

Plan. Invest. Prosper.

DISCLOSURE: Sidoxia Capital Management (SCM) and some of its clients hold long positions in certain exchange traded funds, but at the time of publishing SCM had no direct position in KR, or any other security referenced in this article. No information accessed through the Investing Caffeine (IC) website constitutes investment, financial, legal, tax or other advice nor is to be relied on in making an investment or other decision. Please read disclosure language on IC Contact page

Leave a Comment