Unawareness, beliefs, and speculative trade

► We define a generalized state-space model with interactive unawareness and probabilistic beliefs and show that non-trivial unawareness obtains in such models. ► We show that the common prior assumption is too weak to rule out speculative trade under unawareness in all states. ► We prove a generalized “No-speculative-trade” theorem according to which there cannot be common certainty of strict preference to trade. ► We prove a generalization of the “No-agreeing-to-disagree” theorem.