A theory of information inefficiency of markets

Conventional wisdom is that markets are information efficient. Alas, a simple game-theoretical model illustrates that value traders only have an incentive to invest in research and information if (i) information cost is low enough, (ii) the overall market is sufficiently clueless, and (iii) market makers do not suspect value traders of being well informed. This leaves ample scope for the overall market to remain inefficient, even in the long run, with undesirable consequences for society as a whole.