Recent Results in Semileptonic B Decays With BaBar

In this note, recent results of studies of semileptonic B meson decays from \babar\ are discussed and preliminary results given. In particular, a recent measurement of $\mathcal{B}(B \to D^{(*)}\tau \nu)$ and the ratio $\mathcal{B}(B \to D^{(*)}\tau \nu)/\mathcal{B}(B \to D^{(*)}\ell \nu)$ is presented. For the $D^*$ mode, a branching fraction of 1.79\pm0.13\stat\pm0.17\syst is found, with a ratio of 0.325\pm0.023\stat\pm0.027\syst. For the $D$ mode, the results are 1.04\pm0.12\stat\pm0.14\syst and 0.456\pm0.053\stat\pm0.056\syst, respectively. In addition, a study of $B_s$ production and semileptonic decays using data collected in a center-of-mass energy region above the \Y4S resonance is discussed. The semileptonic branching fraction $\mathcal{B}(B_s \to \ell \nu X)$ is measured to be 9.9{}^{+2.6}_{-2.1}\stat{}^{+1.3}_{-2.0}\syst.Comment: 8 pages, 6 figures, Parallel talk at APS meeting of the Division of Particles and Fields 201

Quality Uncertainty And Adverse Selection In Sponsored Search Markets

Sponsored search mechanisms, where advertisers bid for placement to be as close to the top in the listing of search results, are the fastest growing among online search models. Sponsored search in popular search services such as Google and Yahoo! employ an auction mechanism wherein firms can bid, for a better placement in the (sponsored) search results, on relevant keywords used by consumers in their search process. This provides an unprecedented opportunity to test some of the predictions of earlier research relating quality and advertising, in the online setting. While sponsored search mechanisms have been gaining popularity, they can potentially introduce a bias in the listing of search results. In particular, sponsored search mechanisms that enable low quality bidders to be placed at the top of the search listings can adversely affect consumer welfare. Our study uses data from online sponsored search auctions to examine the relationship between advertisers' quality and their bidding strategies. Specifically we seek to understand if advertisers' bidding strategies differ across products characterized by different degrees of quality-uncertainty. Our results indicate that there are significant differences in the bidding strategies of sellers of search goods as compared to sellers of experience and credence goods, and that there is significant adverse selection in product categories characterized by greater uncertainty. We discuss the implications of our findings for consumers, advertisers, and intermediaries and provide directions for future research in this emerging context

An Empirical Study of Online Software Outsourcing: Signals under Different Contract Regimes

We study whether and how contractual arrangements (fixed price vs. time-and-materials contracts) change the effect of reputation, certification, and language characteristics on the chances of winning outsourcing contracts. Using a comprehensive dataset from an online outsourcing marketplace, we model how buyers choose among bidding vendors, and how the effects of these variables change under different contract forms. Our results show that online reputation is an important predictor of success only for fixed-price contracts, but not significant for times-and-materials contracts. In other words, contract forms can mitigate the typical Matthew Effect associated with online reputation systems. Contrary to popular belief, certifications do not increase the chances of winning regardless of the contract forms. Linguistic features of private communications from the vendor to the buyer also affect the chances of winning, and different dimensions have different effects when contract forms change. Our study is one of the first to study the interaction between contract formats and different signals that vendors can reveal to buyers in the competitive bidding process, and is also one of the first to investigate how texts of private communications affect buyers' contracting decisions

Next Steps: A School District\u27s Guide to the Essential Elements of Service-Learning

We are pleased to share a new tool for service-learning. Next Steps: A School District\u27s Guide to the Essential Elements of Service-Learning is an excellent guide for state level or school district administrators as they create or improve their service-learning program, regardless of their previous experience in service-learning. Students make a tremendous difference in their schools and communities when they are given the opportunity to use their enthusiasm, energy and ideas to problem solve and contribute to the common good. Maryland was the first state to require that all students participate in service-learning to graduate from public high school. Educators and community leaders agreed that service-learning allowed students to use knowledge and skills learned in the classroom to meet the needs of their communities. They also found service-learning to be a highly effective teaching method, allowing students to demonstrate classroom learning in an authentic setting. Since 1992 when we began this educational reform, Maryland\u27s 24 school districts have used Next Steps to strategically plan to strengthen district level infrastructure in order to support quality service-learning experiences for our learners. The experience of creating and revising the delivery of our service-learning programs make our state a leader in the field of service-learning. We are confident that you will benefit from the lessons we have learned. We want to thank the service-learning leaders from around Maryland and across the nation who worked with the Maryland Student Service Alliance to develop this document