EFF/KRF: There is always an issue about how to "properly" measure value. But all the work we have done says that at least for diversified portfolios, it doesn't much matter.
Alternative price ratios, like earnings/price and cashflow/price, work about as well as book/price, in terms of identifying value stocks and growth stocks. Every ratio has its problems because whatever fundamental one puts in the numerator has its own accounting issues. As a result, there are inevitable misclassifications of stocks, but they should wash out in diversified portfolios like ours.
We don't see any special problems with the book/price ratios of financial companies.
Eugene Fama and Ken French are members of the Board of Directors for and provide consulting services to Dimensional Fund Advisors LP.