Stock market crashes in 2007–2009: were we able to predict them?

The article focuses on the bond stock earnings yield differential (BSEYD) model, which relates the yield on stocks to the yield on nominal Treasury bonds. It says that an optimal asset allocation between bonds and stocks is related to their relative yields. It mentions that the BSEYD model causes an equity market correction if the market adjustment is large. It adds that the standard confidence intervals based on a Gaussian assumption proved inaccuracy.