Is CAPE Optimal for Market Valuation, and Useful?

Does Cyclically-Adjusted Price-to-Earnings ratio (CAPE, or P/E10) usefully predict stock portfolio returns? In their October 2017 paper entitled “The Many Colours of CAPE”, Farouk Jivraj and Robert Shiller examine validity and usefulness of CAPE in three ways: (1) comparing predictive accuracies of CAPE at different horizons to those of seven competing valuation metrics (ratios of an income proxy or book value to price); (2) exploring alternative constructions of CAPE based on different firm earnings proxies; and, (3) assessing practical uses of CAPE for asset allocation and relative valuation (supporting rotation among asset classes, countries, sectors or individual stocks). They employ a total return CAPE, assuming reinvestment of all dividends. For forward testing, they lag earnings and related data to ensure real time availability for investment decisions. Using quarterly and annual U.S. stock market data from Shiller since the first quarter (Q1) 1871 dovetailed with end-of-quarter data since Q4 1927, and data as available for other valuation metrics, all through the Q2 2017, they find that: (more…)