How do financial markets switch from states of optimism to pessimism and vice versa? Given that a financial market is currently stable, what is the probability that it will become unstable and crash? We answer those questions in the context of a natural experiment with risk sources of...

In a complete financial market every contingent claim can be hedged perfectly. In an incomplete market it is possible to stay on the safe side by superhedging. But such strategies may require a large amount of initial capital. Here we study the question what an investor can do who is unwilling...

I study the effects of risk and ambiguity (Knightian uncertainty) on optimal portfolios and equilibrium asset prices when investors receive information that is difficult to link to fundamentals. I show that the desire of investors to hedge ambiguity leads to portfolio inertia and excess...

I study the effects of aversion to risk and ambiguity (uncertainty in the sense of Knight (1921)) on the value of the market portfolio when investors receive public information that they find difficult to link to fundamentals and hence treat as ambiguous. I show that small changes in public...

If agents are ambiguity-averse and can invest in productive assets, asset prices can robustly exhibit indeterminacy in the markets that open after the productive investment has been launched. For indeterminacy to occur, the aggregate supply of goods must appear in precise configurations but the...

We show that the hedging benefit of owning a home reduces the variability of housing consumption after a move. When a current home owner's house price covaries positively with housing costs in a future city, changes in the future cost of housing are offset by commensurate changes in wealth...

We develop a zero beta industry model of growth options to explain the conflicting empirical findings on the relation between stock returns and idiosyncratic return volatility at the firm level. By allowing for the volatility of the underlying idiosyncratic choice variables to exhibit...

With model uncertainty characterized by a convex, possibly non-dominated set of probability measures, the investor minimizes the cost of hedging a path dependent contingent claim with given expected success ratio, in a discrete-time, semi-static market of stocks and options. Based on duality...

It is an interesting question that if the implied volatility can perfectly predict the fluctuations of the future share market, and how many days of the changes the implied volatility can effectively predict.The purpose of this paper is to find the answers of the above questions. We calculate...