This paper examines necessary conditions for a demand for new information to exist. In this one-period model, investors are homogeneous, have logarithmic utility, and must decide on information acquisition before trading starts, and without knowing what other investors will do. We examine the...

A costless, fully revealing signalling equilibrium is derived from two easily understandable conditions. The outsidet-protection condition states that the outsiders relate the price which they offer to pay for a security inversely to the supply of this security which they interpret as a quality...