The Random Walk Hypothesis in the Emerging Indian Stock Market

This paper examines the random walk hypothesis in the emerging Indian stock market using daily data on individual stocks. The statistical evidence in this paper rejects the random walk hypothesis. The results suggest that daily returns earned by individual stocks and by an equally weighted portfolio show significant non–linear dependence and persistent volatility effects. The non–linear dependence takes the form of ARCH–type conditional heteroskedasticity and does not appear to be caused by nonstationarity of underlying economic variables. Though conditional volatility is time varying, it does not explain expected returns.     

Product attributes and models of multiple discreteness

Demand for product characteristics is examined within the context of models that allow for both corner and interior solutions corresponding to zero and non-zero demand. Product attribute information is associated with marginal utility and curvature (satiation) parameters of various utility functions. Empirical applications demonstrate the need for incorporating characteristics in a fairly general way. We also compare our approach to an ideal point and pure Lancasterian versions of our nonlinear utility model. The data support our model over either the ideal point or Lancasterian variants.     

Seasonality and non-linear price effects in scanner-data-based market-response models

Scanner data for fast moving consumer goods typically amount to panels of time series where both N and T are large. To reduce the number of parameters and to shrink parameters towards plausible and interpretable values, Hierarchical Bayes models turn out to be useful. Such models contain in the second level a stochastic model to describe the parameters in the first level.     

Econometric analysis of copyrights

This paper explores the impact of copyrights on firm value and on the demand for firm output. Using panel data on franchise value and ticket sales from the National Football League over the 1991–2000 period, we analyze the effect of copyrights (in this case, team logos) using several parametric estimators, the Arellano and Bond [1991. Some tests of specification for panel data: Monte Carlo evidence and an application to employment equations. Review of Economic Studies 58, 277–297] dynamic panel data estimator, and a semi-non-parametric method based on difference-in-differences propensity score matching. We find a negative effect of logo changes on franchise value that is robust across multiple specifications. In addition, logo changes also appear to have a moderate positive, albeit not particularly robust, impact on ticket sales.     

Short sellers and insider trading profitability: A natural experiment

We examine the impact of short sellers on insider trading profitability using a natural experiment of a pilot program which relaxed short-selling constraints for randomly selected pilot stocks. We find that pilot firms experienced a significant decrease in insider trading profitability during the pilot program. The results are more pronounced for the pilot firms with poor information quality, and for the pilot firms without corporate restrictions on insider trading. Our evidence suggests that short sellers serve an important market disciplinary role by reducing insider trading profitability.     

Terrorism activities and long-term annual management forecasts

We study the effects of terrorist attacks on firms’ long-term annual management earnings forecasts bias. We find that the managers of firms located closer to the epicenters of attacks are more likely to issue optimistic long-term annual earnings forecasts relative to the managers of a control group of unaffected firms. The exposure effect is stronger for more severe terrorist events, and firms with more uncertain fundamentals and less geographic diversification. In addition, we document that managers’ forecast optimism intensifies for firms with stronger negative stock market reaction to the terrorist event, for CEOs with higher ability and for companies that are more likely to issue equity or engage in acquisitions following the terrorist event. Overall, our results are consistent with the idea that long-term annual earnings forecasts are used by managers to counterbalance the short-term pessimistic response to terrorist attacks.     

Financial reporting consequences of natural disasters: Evidence from the impact of resource constraints at audit offices on non-affected clients

Disaster-affected clients demand significant additional effort from their audit office, and hence strain the audit office’s resources available to other non-disaster-affected clients. We consider audit offices with disaster-affected clients to be strained offices and find that, compared with clients audited by non-strained audit offices, non-disaster-affected clients audited by strained audit offices are more likely to have their financial statements restated. This result suggests the financial reporting quality of companies not directly exposed to disasters could also be negatively affected by the disasters, due to their auditors’ strained-resource issue. We further find such a negative effect is more pronounced when the degree of resource constraints is greater and when the audit office lacks client experience or industry expertise. We offer novel evidence of financial reporting consequences of natural disasters, focusing on the externality of disasters on companies not directly affected by disasters. The findings have important implications for regulators in making disaster-related policies, for auditors in managing their client portfolios, and for companies in making auditor choice decisions.     

The contracting value of tainted reports in cost reduction settings

While cost accounting is a well-developed discipline with a rich institutional past, it is criticized for being manipulable. This criticism is due, in part, to the existence of multiple, yet equally accepted cost allocation procedures or cost estimation techniques. Employing a principal-agent model, cost accounting is modeled as a menu of alternative methods which, conditional on agent effort, produce noisy, unbiased and independently distributed (i.e., equally defensible) measures from which a single realization is selected ex post as the report used to contract with the agent. Assuming that the report does not indicate which method produced it, the report modeled is “tainted” in that the lowest (most favorable to the agent) outcome is reported, where the “amount” of tainting corresponds to the menu's size. The paper identifies bright-line conditions where the principal's expected net payoff is independent of the amount of tainting, demonstrating that tainting does not necessarily affect the report's incentive value.     

Returns of Small Growth Stocks: An Empirical Analysis

I investigate the mean reversion tendency of small growth stocks. Using a carefully articulated research design employing established and empirically tested principles, my findings should support or refute the anecdotal evidence that small growth stocks make superior investments. The primary motivation for the study springs from the documented differential preference among investors for value and growth stocks. Despite evidence that value stocks tend to outperform growth stocks, investors retain strong interest in growth stocks. Yet in examining the performance of Business Week’s (BW), smaller capitalization companies (called “Hot Growth Companies”) with respect to the overall financial market, Bauman et al. [2002] found positive excess returns in the pre-publication period but negative excess returns in the post-publication period. A limitation of their study is that their analyses relied on only three criteria: sales, BW rank and return on capital, which do not represent completely a firm’s financial health. I replicate Bauman et al.’s study but use a more robust and representative variable set to test the mean reversal hypothesis — Forbes’ financial criteria — and I focus on six variables. In the current study, I look at 4,200 companies listed in Forbes from 1980 to 2000. The results of the expanded study substantiate Bauman et al.’s [2002] study showing that there are positive excess returns in the pre-publication period, but negative excess returns in the post-publication period. An expanded future study will look at five additional variables to see if they make a significant difference on the effects of the returns of small growth stocks.     

THE JOINT ARRIVAL AND DEPARTURE PROCESS FOR THE M/M/l QUEUE

We consider the M/M/1-queue and derive an explicit expression for the joint distribution of the number of arrivals and the number of departures in [0, t), given the number of customers initially present. The derivation is almost purely combinatorial, it avoids the use of generating functions, and immediately yields a simple probabilistic interpretation of the result.