We study dynamic equilibrium behavior of security prices in an economy where non-fundamental risk arises from agents' heterogeneous beliefs about extraneous processes. We provide a complete characterization of equilibrium in terms of the primitives of the economy, via construction of a representative agent with stochastic weights. Besides the standard pricing of fundamental risk, an agent now also prices the non-fundamental risk with a market price which is a risk-tolerance weighted average of his extraneous disagreement with all remaining agents. Consequently, for given risk tolerances, agents' perceived state prices and consumption streams are more volatile in the presence of extraneous risk. The interest rate inherits additional terms arising from agents' misperceptions about consumption growth, and from precautionary savings motives against the non-fundamental uncertainty.

This paper solves a dynamic general equilibrium asset pricing model of disagreement that draws a direct link between asset prices and the financial volume of trade. The model exhibits two risk averse agents that hold heterogeneous beliefs about the conditional mean of the aggregate consumption growth. The differences in opinions is supported by the fact that agents interpret public information differently. The connecting link between prices and volume is an exogenously time varying disagreement intensity that determines the magnitude of disagreement about new information. The model is able to explain a number of seemingly unrelated asset pricing facts namely the positive correlation between price changes and volume, the contemporaneous relation between volume and return volatility, the excess volatility, the volatility persistence and the negative correlation between price levels and volatility.

This paper studies the interaction of borrowing and short-sale constraints and their ultimate effects on asset pricing properties in a simultaneous presence of the constraints in a dynamic general equilibrium model with heterogeneous risk aversions and heterogeneous beliefs in the aggregate cash flow growth. The constraints negate the binding of each other, and hence they virtually never bind at once. Instead, there exist clear regions with alternative binding modes of the constraints with different constraints more likely to bind in different states of economy. The borrowing constraint is more active in bad times and the short-sale constraint is so in good times. The constraints bind intermittently--alternately at times--in transitory states of economy where their relative strength is balanced. Qualitatively matching empirically documented patterns of asset prices, I find that the constraints moderate their price effects but amplify their negative volatility effects, thereby can help curb the market volatility. However, a motive for speculation, featured by a speculative premium, arises due to any constraints, and thus can exist in any states of economy, not only in good times.

We analyze the joint effect of borrowing and short-sale constraints in a dynamic economy populated by two constrained investors with heterogeneous risk aversions and beliefs. We find that equilibrium prices adjust in such a way that the constraints never simultaneously bind. When the constraints are tight, we observe a regime switch behavior (discontinuities) in the risk-free rate and market price of risk at a critical state, where two equilibria exist, i.e., either constraint can be binding. Stock return volatility is the lowest at the critical state. Imposing a ban on short-sales at the same time when access to credit is restrictive or tightening borrowing during a short-sale ban can potentially move the equilibrium away from the critical state, thus increase stock return volatility rather than reducing it.