Security–Relative Information Market Efficiency: Some Empirical Evidence

Abstract

Commonly defined, a market is efficient if prices always fully reflect available information. That market might be viewed as consisting of two major segments: an information market and pricing mechanism. The efficiency has been amply documented elsewhere. The information market, however, should be afforded increased attention. In particular, the efficiency of the information market may vary across securities and with respect to particular securities, across time. Stated another way, the degree of imperfection in the information market may vary across securities and across time, resulting in a relative efficiency phenomenon. The presence of such a phenomenon would offer research opportunities yielding a greater understanding of the functioning of the information market and the pricing of securities.