stock market's duration

On a valuation front, we estimate that the S&P 500 is likely to achieve an average total return over the coming decade of about 4.8% annually. This is certainly better than the projected returns that we have observed over much of the past decade, but then, the past decade has produced virtually no total return for equity investors at all. An expected total return of 4.8% is also clearly better than is presently available on Treasury bills, which are priced to return a single basis point of interest annually, and is also better than the sub-2% yield available on 10-year Treasury debt.
The problem is that the duration of a 10-year Treasury bond is only about 7 years, which is not only the weighted average time it takes to receive the future stream of payments, but also conveniently measures the expected percentage change in the bond price for a 1% change in long-term return. For stocks, the "duration" mathematically works out to be roughly the price/dividend ratio, which is about 45 for the S&P 500. Put simply, in order to achieve a given increase in long-term expected return, stocks would have to suffer about 6 times the price decline that bonds would experience. Stocks may very well outperform Treasury bonds over the coming decade, but for investors who have any sensitivity to price volatility, that is likely to be a small comfort in the next few years. We estimate that the S&P 500 would have to trade at about the 800 level in order to achieve 10-year prospective returns of 10% annually. Importantly, even a magical "fix" out of Europe would do nothing to change that algebra.