What happened to the so-called Fed model? Although
it was never actually endorsed by the Federal Reserve, the idea of
comparing the 10-year Treasury yield and the earnings yield (earnings
divided by price) on the S&P 500 (SNPINDEX: ^GSPC ) has become a standard valuation tool for many investors. Moreover, for investors in SPDR S&P 500 (NYSEMKT: SPY ) or the iShares Core S&P 500 (NYSEMKT: IVV )
, a view on the value and future direction of the indexes is a critical
part of investing. So how useful is the model, and what can investors
learn from it?
Introducing the Fed model
As usual with valuation methodologies, there is no end of disagreement over which input factors to use. For reference, the earnings used in the following charts is as-reported, rather than adjusted. All of the raw data used comes from Noble prize winning economist Robert Shiller's website at Yale.
As usual with valuation methodologies, there is no end of disagreement over which input factors to use. For reference, the earnings used in the following charts is as-reported, rather than adjusted. All of the raw data used comes from Noble prize winning economist Robert Shiller's website at Yale.
The basic theoretical idea behind the model is
simple. An investor faced with buying bonds or equities might choose
between a 10-year U.S. Treasury yielding, say 5%, or buying an equity
with an earnings yield (earnings/price) of 5%. Roughly speaking, when
the Treasury yield is below that of equities then it makes sense to buy
equities, and vice versa.
The following chart compares the long-term
performance of these two variables. As a rough guide, when the earnings
yield (in red) is above the 10-year Treasury yield (in blue) then equity
markets are seen to be cheap and vice versa.
Yes, you are reading the chart correctly! The model
is implying that the S&P 500 is a screaming buy right now. So does
that mean that equity investors should just pile into index ETFs and
enjoy the ride upward?
The answer depends on how much you trust the model.
A false friend
The model became popular in the '80s and '90s because it appeared to provide a very useful way to judge the future direction of the S&P 500. In fact, plotting the 10-year yield (x-axis) against the S&P 500 P/E ratio (y-axis) and performing a regression analysis on the data produces a remarkable result.
The model became popular in the '80s and '90s because it appeared to provide a very useful way to judge the future direction of the S&P 500. In fact, plotting the 10-year yield (x-axis) against the S&P 500 P/E ratio (y-axis) and performing a regression analysis on the data produces a remarkable result.
The best-fit trendline in the chart generates an
equation with a coefficient of determination, or R^2, of 0.83; a result
which indicates a very strong relationship. In plain English, the
equation (rounded up) of y=0.98x-1.5 means that for a 10-year yield of,
say 5%, the S&P 500 earnings yield should be equal to
0.98*5-0.015=4.9%. Since the earnings yield is the inverse of the P/E
ratio, this implies a P/E ratio of around 20 times.
It's not hard to see why this metric became
popular, because from 1980-2000 it appears to offer a failsafe way of
investing in bonds or equities!
However, Foolish readers will note from the first
chart that the relationship seems to break down after the year 2000. In
fact, from 2003-2013 there is only one period where equities where not
"cheap." That's 2009 when earnings (and therefore the earnings yield)
collapsed during the recession.
Three explanations
There are many ways to interpret the relative cheapness of equities to bonds right now, or rather to interpret what the market is interpreting on the issue.
There are many ways to interpret the relative cheapness of equities to bonds right now, or rather to interpret what the market is interpreting on the issue.
One approach suggests that bond yields are being
artificially held down by massive injections of liquidity by the Federal
Reserve. Therefore, equity investors may be saying that they don't
really believe that equities are relatively cheap, because either
interest rates will inevitably go up in a few years or earnings will
fall in the future. Alternatively, both events could happen
concurrently. For example, a collapse of confidence in lending to the
U.S. could lead to Treasury yields rising, with damaging effects on
corporate growth. However, if equity investors think that interest rates
will go up, then why not just short bonds via something like the iPath US Treasury 10-year Bear ETN (NYSEMKT: DTYS )
Another explanation is that investors are afraid of
a cataclysmic event in the future, and don't wish to hold equities.
Indeed, every recent global recession seems to have been deeper than the
last. Moreover, the U.S. public debt situation is such that the U.S.
(and the global economy) could face a severe and lasting depression if
another recession takes place in the next few years.
The third explanation is that asset classes'
valuations tend to be the product of a combination of fundamentals and
waves of enthusiasm that come in to the sector. It was equities in the
late '90s, then property in the early 2000s, then oil and commodities,
then it was gold, and now it's emerging market bonds.
The bottom line
Unfortunately, the Fed model doesn't provide a catch-all solution to asset class allocation. Any valuation method needs to be put into the context of the overall investment environment, and while it's easy to argue that the Fed model works under "steady state" conditions (such as between 1980-2000) it's a lot harder to predict when those conditions will come about again. Investing just isn't that simple.
Unfortunately, the Fed model doesn't provide a catch-all solution to asset class allocation. Any valuation method needs to be put into the context of the overall investment environment, and while it's easy to argue that the Fed model works under "steady state" conditions (such as between 1980-2000) it's a lot harder to predict when those conditions will come about again. Investing just isn't that simple.