"Discount rate variation is the central organizing question of current asset pricing research. I survey facts, theories and applications. We thought returns were uncorrelated over time, so variation in price-dividend ratios was due to variation in expected cashflows. Now it seems all...

"We show that long run consumption risk models imply that the covariance matrix of the logarithm of price to dividend (P/D) ratios of stocks has a strict factor structure. Factor analysis of the P/D ratios of 25 portfolios formed by sorting stocks based on their size and book to market ratio...