Academics conclude that the model is inconsistent with a rational valuation of the stock market, or past long-term observations, and has little predictive forecasting power. In addition, the Fed model only seems to apply for specific periods in the United States, while international markets have shown weak evidence with long period of dramatic divergences (e.g. Japan post-1990, US post dot-com burst).
Lack of theoretical support The competing asset argument listed above argues that only when stocks have the same earnings yield as nominal government bonds, that both asset classes are equally attractive to investors. But the earnings yield (E/P) of a stock does not describe what an investor actually receives as not all earnings are paid out to the investor (either via dividends or
share buybacks). In addition, corporate bonds (with a yield above the government bond yield as a risk premium), do not fit into the Fed model of valuation, which therefore implicitly assumes that equities have the same risk profile as government bonds. : P= \frac{D (1 + G)}{R_{\text{f}} + RP - G} P is the price, and D the dividend, G the expected long-term growth rate, R_{\text{f}} the risk-free rate (10-year nominal treasury notes), and RP the
equity risk premium; then making the following assumptions:
Data selection and international markets The Fed model equilibrium was only observed in the United States, and for specific time periods, namely 1921 to 1928 and 1987 to 2000; outside of this time window, or in various other international markets, equities and Treasury yields do not show the relationship outlined in the Fed model. In 2017, Stuart Kirk, head of Deutsche Bank's DWS Global Research Institute and a former editor of the Financial Times
Lex column, wrote of DWS's analysis of the long-term data: "In other words no historical relationship between bond yields and dividend yields. By extension, this means that interest rates have nothing to do with share prices either as the former lead bond yields while dividend yields move with earnings yields (the latter being the inverse of the price/earnings ratio). Yes, correlations can be found in the short run, but they are statistically meaningless".
Lack of predictive power A test of whether the Fed model is an equity valuation theory with descriptive validity is that it should be able to identify over-valued and under-valued assets. The analysis shows that the Fed model has no power to forecast long term stock returns, and even crude traditional
value investing methods that use only the market's P/E have significantly more efficacy than the Fed model. In 2018,
Ned Davis Research ran a test of the Fed model's ability to predict subsequent 10-year returns using data from the previous 75 years. Davis found that "it was basically worthless", and that it's
r-squared metric of 0.5%, compared poorly that those of other ratios, including
P/E (56.3%),
P/Sales (67.2%), and Households' equity allocation as a % of Total Financial Assets (88.4%). In June 2020, finance author
Mark Hulbert, ran a statistical test from 1871 to 2020 of the Fed Model's ability to forecast the stock market's inflation-adjusted real return over subsequent 1, 5, and 10-year periods, and found that adding long-term Treasury yields, per the Fed model, materially
reduced the predictive power of just using the earnings yield (E/P) on its own.
Breakdown at very low interest rates It has been shown that the relationship between the forward earnings yield and long-term Government bond yields can more substantially breakdown during periods of very low-interest rates, and particularly very low real rates of interest, either from natural effects or by deliberate central banking actions such as quantitative easing. Similarly, on the bursting of the dot-com bubble in 2002, despite the Fed reducing long-term rates post-2002, the earnings yield of the S&P500 rose consistently for the next decade from 4 percent to 9 percent, while long-term Treasury yields fell from 6 percent to 2 percent. ==Impact of Fed put==