By GuruFocus
Prof. Robert Shiller of Yale University invented the Schiller P/E to measure the market’s valuation. The Schiller P/E is a more reasonable market valuation indicator than the P/E ratio because it eliminates fluctuation of the ratio caused by the variation of profit margins during business cycles. This is similar to market valuation based on the ratio of total market cap over GDP, where the variation of profit margins does not play a role either.
