First, there was considerably less access to information in 1984 than now, so the market almost certainly was less efficient. Second, thanks to Fama and French

First, there was considerably less access to information in 1984 than now, so the market almost certainly was less efficient. Second, thanks to Fama and French, we now know that there is indeed a value premium. However, the majority view is that it is a risk premium: still useful because it exposes one to different risk than pure market beta, but not a free lunch. (Also it is most likely more efficient to capture the premium using low-cost "tilted" (value) funds, rather than by picking individual stocks and unnecessarily taking on unsystematic risk.)