Stock price reaction following large one-day price changes: UK evidence

We examine the short-term price reaction of 424 UK stocks to large one-day price changes. Using the GJR-GARCH(1,1), we find no statistical difference amongst the cumulative abnormal returns (CARs) of the Single Index, the Fama–French and the Carhart–Fama–French models. Shocks ?5% are followed by a significant one-day CAR of 1% for all the models. Whilst shocks ?−5% are followed by a significant one-day CAR of −0.43% for the Single Index, the CARs are around −0.34% for the other two models. Positive shocks of all sizes and negative shocks ?−5% are followed by return continuations, whilst the market is efficient following larger negative shocks. The price reaction to shocks is unaffected when we estimate the CARs using the conditional covariances of the pricing variables.     

Bias from Farmer Self‐Selection in Genetically Modified Crop Productivity Estimates: Evidence from Indian Data

In the continuing debate over the impact of genetically modified (GM) crops on farmers of developing countries, it is important to accurately measure magnitudes such as farm‐level yield gains from GM crop adoption. Yet most farm‐level studies in the literature do not control for farmer self‐selection, a potentially important source of bias in such estimates. We use farm‐level panel data from Indian cotton farmers to investigate the yield effect of GM insect‐resistant cotton. We explicitly take into account the fact that the choice of crop variety is an endogenous variable which might lead to bias from self‐selection. A production function is estimated using a fixed‐effects model to control for selection bias. Our results show that efficient farmers adopt Bacillus thuringiensis (Bt) cotton at a higher rate than their less efficient peers. This suggests that cross‐sectional estimates of the yield effect of Bt cotton, which do not control for self‐selection effects, are likely to be biased upwards. However, after controlling for selection bias, we still find that there is a significant positive yield effect from adoption of Bt cotton that more than offsets the additional cost of Bt seed.     

The Interstate River Compact as a Water Allocation Mechanism: Efficiency Aspects

Interstate river compacts are widely used to allocate water among riparian states. Twenty-one compacts are currently in force in the western United States, and these compacts are mostly of two types: those that allocate a fixed amount or flow of water to individual states; and those that allocate percentages of available water to the riparian states. This study compares the performance of the two resulting allocations with that resulting from basin-wide optimization without compact constraints. While widely varying hydrologic and economic characteristics of river basins create a large set of possible outcomes, a range of stylized case studies indicates that percentage compacts are likely to generate greater net benefits and to result in more equitable risk-sharing than fixed compacts under many circumstances. In light of recent compact negotiations in the southeastern United States, it is recommended that efficiency analyses under present and future conditions be made a part of all compact negotiations.     

机遇,你抓对了么

正一旦他们看准并研究透彻了特定市场上的机遇,就会制定一套聚焦战略,将注意力牢牢锚定他们认为最佳的机会,这会让战略家们一次性收获一个领域的多个机遇,而非相互割裂的一个个机会机遇稍纵即逝。对于任何企业,抓住新的增长机遇都具有战略意义上的重要性,这种重要性体现在公司整体发展、业务创新、营销创意等各个方面。更重要的是,在新的竞争环境下,公司越来越看重变革与灵活,那么是否过去强调聚焦度的战略就不再重要?