By applying Bai and Perron's [Bai, J., Perran, P., 1998. Estimating and testing linear models with multiple structural changes. Econometrica 66, 47-78] change-point model, we pinpoint the exact dates for structural breaks in the book-to-market premium. We find that overall the BM premium is...

We provide a new upper bound on the R-squared of a predictive regression of stock returns on predictable variables, tightening substantially Ross's (2005) bound. An empirical application illustrates that while Ross's bound is not binding, our bound does.