In this paper, we derive and experimentally test a theoretical model of speculation in multi-period asset markets with public information flows. The speculation arises from the traders’ heterogeneous posteriors as they make different inferences from sequences of public information. This leads to overpricing in the sense that price exceeds the most optimistic belief about the real value of the asset. We find evidence of speculative overpricing in both incomplete and complete markets, where the information flow is a gradually revealed sequence of imperfect public signals about the state of the world. We also find evidence of asymmetric price reaction to good news and bad news, another feature of equilibrium price dynamics under our model. Markets with a relaxed short-sale constraint exhibit less overpricing.

We develop a competitive equilibrium theory of a market for votes. Before voting on a binary issue, individuals may buy and sell their votes with each other. We define the concept of ex ante vote-trading equilibrium and show by construction that an equilibrium exists. The equilibrium we characterize always results in dictatorship if there is any trade, and the market for votes generates welfare losses, relative to simple majority voting, if the committee is large enough or the distribution of values is not very skewed. We test the theoretical implications in the laboratory using a continuous open-book multiunit double auction.