[We present a dynamic contracting model in which the principal and agent disagree about the resolution of uncertainty, and we illustrate the contract design in an application with Bayesian learning. The disagreement creates gains from trade that the principal realizes by transferring payment to states that the agent considers relatively more likely, changing incentives. The interaction between incentive provision and learning creates an intertemporal source of "disagreement risk" that alters optimal risk sharing. There is an endogenous regime shift between economies with small and large belief differences, and an early shock to beliefs can lead to large persistent differences in variable pay even after beliefs have converged. Under risk-neutrality, "selling the firm" to the agent does not implement the first-best because it precludes state-contingent trades.]

[Compared to mutual funds, hedge funds prefer smaller, opaque value securities, and have higher turnover and more active share bets. Decomposing returns into three components, we find that hedge funds are better than mutual funds at stock picking by only 1.32% per year on a value-weighted basis, and this result is insignificant on an equal-weighted basis or with price-to-sales benchmarks. Hedge funds exhibit no ability to time sectors or pick better stock styles. Surprisingly, we find only weak evidence of differential ability between hedge funds. Overall, our study raises serious questions about the perceived superior skill of hedge fund managers.]

[Theory suggests that greater hierarchical distance between a subordinate and his boss makes it more difficult to share abstract and subjective information in decision making. A novel dataset put together from credit dossiers of large corporate loan applicants enables us to observe the information collected by loan officers, and how it is used by the ultimate loan approving officer. We find that greater hierarchical/geographical distance between the information collecting agent and the loan approving officer leads to less reliance on subjective information and more on objective information. By exploiting nonlinearities in the "assignment rules" that determine an applicant's hierarchical distance, and using information collecting agent fixed effects, we show that our result cannot be driven by endogenous assignment of applicants. We also find that higher frequency of interactions between the information collecting agent and loan approving officer, both over time and through geographical proximity, helps mitigate the effects of hierarchical distance on information use. Our results show that hierarchical distance influences information use, and highlights the importance of "human touch" in communication.]

[We study the trading of individual investors using transaction data and identifying buyer- or seller-initiated trades. We document four results: (1) Small trade order imbalance correlates well with order imbalance based on trades from retail brokers. (2) Individual investors herd. (3) When measured annually, small trade order imbalance forecasts future returns; stocks heavily bought underperform stocks heavily sold by 4.4 percentage points the following year. (4) Over a weekly horizon, small trade order imbalance reliably predicts returns, but in the opposite direction; stocks heavily bought one week earn strong returns the subsequent week, while stocks heavily sold earn poor returns.]

[We propose a new hypothesis-testing method for multipredictor regressions in small samples, where the dependent variable is regressed on lagged variables that are autoregressive. The new test is based on the augmented regression method (Amihud and Hurvich, 2004), which produces reduced-bias coefficients and is easy to implement. The method's usefulness is demonstrated by simulations and by testing a model where stock returns are predicted by two variables, income-to-consumption and dividend yield.]

[We model demand-pressure effects on option prices. The model shows that demand pressure in one option contract increases its price by an amount proportional to the variance of the unhedgeable part of the option. Similarly, the demand pressure increases the price of any other option by an amount proportional to the covariance of the unhedgeable parts of the two options. Empirically, we identify aggregate positions of dealers and end-users using a unique dataset, and show that demand-pressure effects make a contribution to wellknown option-pricing puzzles. Indeed, time-series tests show that demand helps explain the overall expensiveness and skew patterns of index options, and cross-sectional tests show that demand impacts the expensiveness of single-stock options as well.]

[Widespread violations of stochastic dominance by 1-month S&P 500 index call options over 1986-2006 imply that a trader can improve expected utility by engaging in a zero-net-cost trade net of transaction costs and bid-ask spread. Although precrash option prices conform to the Black-Scholes-Merton model reasonably well, they are incorrectly priced if the distribution of the index return is estimated from time-series data. Substantial violations by postcrash OTM calls contradict the notion that the problem lies primarily with the left-hand tail of the index return distribution and that the smile is too steep. The decrease in violations over the postcrash period of 1988-1995 is followed by a substantial increase over 1997-2006, which may be due to the lower quality of the data but, in any case, does not provide evidence that the options market is becoming more rational over time.]

[Many investors purchase mutual funds through intermediated channels, paying brokers or financial advisors for fund selection and advice. This article attempts to quantify the benefits that investors enjoy in exchange for the costs of these services. We study broker-sold and direct-sold funds from 1996 to 2004, and fail to find that brokers deliver substantial tangible benefits. Relative to direct-sold funds, broker-sold funds deliver lower risk-adjusted returns, even before subtracting distribution costs. These results hold across fund objectives, with the exception of foreign equity funds. Further, broker-sold funds exhibit no more skill at aggregate-level asset allocation than do funds sold through the direct channel. Our results are consistent with two hypotheses: that brokers deliver substantial intangible benefits that we do not observe and that there are material conflicts of interest between brokers and their clients.]

[Using eight thousand public companies, we study the impact of the Sarbanes-Oxley Act (SOX) of 2002 and other contemporary reforms on directors and boards, guided by their impact on the supply and demand for directors. SOX increased directors' workload and risk (reducing the supply), and increased demand by mandating that firms have more outside directors. We find both broad-based changes and cross-sectional changes (by firm size). Board committees meet more often post-SOX and Director and Officer (D&O) insurance premiums have doubled. Directors post-SOX are more likely to be lawyers/consultants, financial experts, and retired executives, and less likely to be current executives. Post-SOX boards are larger and more independent. Finally, we find significant increases in director pay and overall director costs, particularly among smaller firms.]

[We examine short selling in US stocks based on new SEC-mandated data for 2005. There is a tremendous amount of short selling in our sample: short sales represent 24% of NYSE and 31% of Nasdaq share volume. Short sellers increase their trading following positive returns and they correctly predict future negative abnormal returns. These patterns are robust to controlling for voluntary liquidity provision and for opportunistic risk-bearing by short sellers. The results are consistent with short sellers trading on short-term overreaction of stock prices. A trading strategy based on daily short-selling activity generates significant positive returns during the sample period.]