Monday 4 February 2013

The S&P 500 Cyclically Adjusted PE (aka S&P 500 or Shiller PE10 or CAPE) – February 2013 Update

The US stock market has seen some large gains since New Year’s Eve. As I write this post the mid market price for the S&P500 is down 0.9% on the day at 1,499.8 but still up 5.2% in little over a month. Similarly, the Dow Jones is down 0.8% at 13,903.5 but is up 6.1% since the market close on the 31 December 2012. It’s therefore appropriate to run the standard Retirement Investing Today monthly update for the S&P500 Cyclically Adjusted PE (S&P 500 CAPE). Let’s see if the market is just exuberant or starting to head towards Irrational Exuberance.  Last month’s update can be found here.

As usual before we look at the CAPE let us first look at other key S&P 500 metrics:
  • The S&P 500 Price is currently 1,500 which is a rise of 1.3% on last month’s average close of 1,480 and 13.3% above this time last year’s monthly Price of 1,324.
  • The S&P 500 Dividend Yield is currently 2.1%.
  • The S&P As Reported Earnings (using a combination of actual and estimated earnings) are currently $88.85 for an Earnings Yield of 5.9%.
  • The S&P 500 P/E Ratio is currently 16.9 which is up from last month’s 16.8.

The first chart below provides a historic view of the Real (inflation adjusted) S&P 500 Price and the S&P 500 P/E.  The second chart below provides a historic view of the Real (after inflation) Earnings and Real (after inflation) Dividends for the S&P 500.

Chart of the S&P500 Cyclically Adjusted PE, S&P500 PE and Real S&P500
Click to enlarge

Chart of Real S&P500 Earnings and Real S&P500 Dividends
Click to enlarge

As always let us now turn our attention to the metric that this post is interested in which is the Shiller PE10.  This is also shown in the first chart which dates back to 1881 and is effectively an S&P 500 cyclically adjusted PE or CAPE for short.  This method is used and was made famous by Professor Robert Shiller.  It is simply the ratio of Real (ie after inflation) S&P 500 Monthly Prices to 10 Year Real (ie after inflation) Average Earnings. 

It is important to highlight that my calculation method varies from that of Professor Shiller.  He only uses S&P 500 Actual Earnings data where because I use the S&P 500 PE10 to actually make investment decisions from I also include extrapolated Earnings estimates right up to the present day.  This is to try and make the value as current as possible.

The key S&P 500 CAPE/PE10 metrics are:
  • The S&P 500 PE 10 is currently 22.2 which is 0.9% above last month’s 22.0.
  • The correlation between the Nominal S&P500 Price and the S&P 500 PE10 from present day back to 1881 is 0.66.  This correlation is a moderate bordering on strong correlation and is one reason why I use this metric to make investment decisions from.
  • The Dataset Average S&P 500 PE10 which dates back to 1881 is 16.5.  Assuming this is “fair value” it indicates that the S&P500 is now some 35% overvalued.
  • The Dataset Median S&P PE10 is 15.9.
  • The Dataset 20th Percentile S&P 500 PE10 is 11.1.
  • The Dataset 80th Percentile S&P 500 PE10 is 20.9.  This means that the PE10 is also well above the 80th percentile.

The chart below further highlights why I use the Shiller PE10 to drive a tactical portion of my Retirement Investing Today asset allocation which is stacked on top of a basic strategic asset allocation.  This shows a chart of the S&P 500 vs the Nominal 5 Year Total Return from January 1881 through to February 2008.  The correlation is -0.46 with an R^2 of 0.21.  This implies that there is a moderate correlation between the S&P 500 PE10 and future returns from the market.  With the PE10 at 22.2 the trendline implies a person buying today could expect a future Nominal 5 Year Total Return of around 35%.  In contrast the Real (inflation adjusted) 5 Year Total Return (not shown in any chart today) trendline implies a return of 21%.

Chart of the S&P500 versus the 5 Year Total S&P500 Return
Click to enlarge

So what of my Retirement Investing Today portfolio.  Regular readers will know that I use the above PE10 data to set my allocation to the International Equities portion of my portfolio.  This is strategically set at 15% of total assets and is targeted to consist of 40% US Equities, 40% Europe Equities and 20% Japan Equities.  I then add the S&P500 PE10 tactical spin on top of this with a target of 10.5% allocation should the PE10 climb to 26.5 (Average PE10+10) or 19.5% should the PE10 fall to 6.5 (Average PE10-10).  Therefore today my tactical allocation sets itself below 15% at 12.4%.

As always do your own research.

Assumptions include:
  • S&P500 Prices are month averages except February 2013 which is a 04 February 2013 mid market Price.
  • January and February 2013 Dividend is assumed to be equal to the December 2012 Dividend
  • October 2012 to February 2013 reported earnings are estimates from Standard & Poor’s. 
  • Inflation data from the Bureau of Labor Statistics.  January and February 2013 inflation is extrapolated.
  • Historic data provided from Professor Shiller website.


  1. Hello, I am new to your site but am impressed by your analysis.

    One question I have (and apologies if you have covered elsewhere) is what would be driving a long term upward trend in the CAPE? I could see that underlying demand for wealth assets (retirement funds etc) could drive an upward trend. I could also see that there is increased confidence in future earnings (perhaps through management skills, technology etc). However, I could see risk and volatility also increasing over the long term which might exert downward pressures.

    Would be interested in your thoughts.

    Best regards

    1. Hi Anonymous

      My personal investment approach (formed based on a lot of reading and analysis) is based around there being no long term upward trend in the CAPE. Instead I believe while there can be exuberance, even irrational exuberance (possibly for long periods of time) along with under shoots everything will ultimately revert to its mean value. This is the case whether we are talking Tulip Bulbs or the S&P500.

      I say this also believing the market can remain irrational longer than I can remain solvent which keeps me an investing rather than trading.