Mechanism and Application of Baker–Venkataraman O→C Acyl Migration Reactions

This literature review focuses on the O→C acyl migration of aryl esters to yield the corresponding 1,3-dicarbonyl products—a reaction known as the Baker–Venkataraman rearrangement—and outlines their subsequent transformations. The purpose of the review is to highlight the utility of the rearrangement which provides a key step in the synthesis of various heterocyclic motifs. The scope of the Baker–Venkataraman rearrangement is illustrated by way of numerous examples of its application, and in doing so, the review contains over 100 references and covers just over 100 years of the literature, from the first report of the rearrangement by Auwers in 1910 up to more recent examples in the past few years. 1 Introduction 2 Historical Perspective 3 Mechanism 4 Applications: General Routes to Heterocycles 4.1 Flavones and Flavanones 4.2 Xanthones 4.3 Chromones 4.4 Coumarins 4.5 Anthrapyran and Anthracyclin Antibiotics 4.6 Benzopyrans 5 The Retro-Baker–Venkataraman Rearrangement 6 Summary and Outloo

Revenue Sharing, Demand Uncertainty, and Vertical Control of Competing Firms

This paper argues that revenue sharing is a valuable instrument in vertically separated industries when there is intrabrand competition among the downstream firms, demand is stochastic or variable, and downstream inventory is chosen before demand is realized. In these environments, the upstream firm would like to simultaneously soften downstream competition and encourage efficient inventory holding. Traditional two-part tariffs cannot achieve both objectives in the presence of downstream competition. Raising the price of the inputs softens price competition but distorts the downstream firms' inventory decisions. We argue that revenue sharing, combined with a low input price, aligns the incentives in the vertical chain. The use of revenue sharing in video rental retailing is discussed. Blockbuster in particular has used revenue sharing in conjunction with heavy marketing of availability to grow significantly in the video rental retail industry. Many other outlets use revenue sharing as well. Some antitrust concerns have been raised by smaller firms suggesting that revenue sharing might be an anticompetitive vertical restraint. Although our model does not address retailer market power, we show that revenue sharing contracts can be used by upstream firms increase inventory holding and consumer welfare.

Socioeconomic Differences in the Adoption of New Medical Technologies

New medical technologies hold tremendous promise for improving population health, but they also raise concerns about exacerbating already large differences in health by socioeconomic status (SES). If effective treatments are more rapidly adopted by the better educated, SES health disparities may initially expand even though the health of those in all groups eventually improves. Hypertension provides a useful case study. It is an important risk factor for developing cardiovascular disease, the condition is relatively common, and there are large differences in rates of hypertension by education. This paper examines the short and long-term diffusion of two important classes of anti-hypertensives - ACE inhibitors and calcium channel blockers - over the last twenty-five years. Using three prominent medical surveys, we find no evidence that the diffusion of these drugs into medical practice favored one education group relative to another. The findings suggest that - at least for hypertension - SES differences in the adoption of new medical technologies are not an important reason for the SES health gradient.

Product Variety and Demand Uncertainty

We show that demand uncertainty leads to vertical product differentiation even when consumers are homogeneous. When a firm anticipates that its inventory or capacity may not be fully utilized, product variety can reduce its expected costs of excess capacity. When the firm offers a continuum of product varieties, the highest quality product has the highest profit margins but the lowest percentage margin, while the lowest quality product has the highest percentage margin but the lowest absolute margin. We derive these results in both a monopoly model and a variety of different competitive models. We conclude with a discussion of empirical predictions together with a brief discussion of supporting evidence available from marketing studies.

Does the Plaintiff Matter?: An Empirical Analysis of Lead Plaintiffs in Securities Class Actions

With the enactment of the Private Securities Litigation Reform Act of 1995 (PSLR) the U.S. Congress introduced sweeping substantive and procedural reforms for securities class actions. A central provision of the Act is the lead plaintiff provision, which creates a rebuttable presumption that the investor with the largest financial interest in a securities fraud class action should be appointed the lead plaintiff for the suit. The lead plaintiff provision was adopted to encourage a class member with a large financial stake to become the class representative. Congress expected that such a plaintiff would actively monitor the conduct of a securities fraud class action so as to reduce the litigation agency costs that may arise when class counsel\u27s interests diverge from those of the shareholder class. Now, more than ten years after the enactment of the lead plaintiff provision, the claim that the lead plaintiff, and particularly the lead plaintiff that is an institutional investor, is a more effective monitor of class counsel in securities fraud class actions continues to be intuitively appealing, but remains unproven. In this study, Professors Cox and Thomas inquire anecdotally and empirically whether the lead plaintiff provision has performed as projected. The anecdotal evidence they uncover is mixed: in some instances demonstrating the virtues of the lead plaintiff provision, while in others showing that the provision has encountered difficulties, including hesitance among institutional lead plaintiffs to take on the burden of serving as lead plaintiff (though recently more institutional investors are taking on the role of lead plaintiff) and allegations of pay-to-play schemes between plaintiffs\u27 law firms and potential lead plaintiffs. Professors Cox and Thomas then conduct a series of statistical analyses of the lead plaintiff provision\u27s costs and benefits. Surprisingly, their results indicate that the ratio of settlement amounts to estimated provable losses in securities class actions---the most important indicator of whether investors have been compensated for their damages---has been lower since the passage of the PSLRA and that settlement size has not increased since the passage of PSLRA. However, they also find that the presence of an institutional investor increases the dollar amount of settlements in those cases in which they appear, suggesting that the current trend for institutional investors to be lead plaintiffs in securities class actions will positively affect average settlement size in such actions in the future. Their analysis also sheds new light on the relative impacts other types of lead plaintiffs, such as individuals versus an aggregation of individuals, have on the outcome of settlements. They conclude with a discussion of the policy implications of their findings

SEC Enforcement Heuristics: An Empirical Inquiry

This Article examines the overlap between SEC securities enforcement actions and private securities fraud class actions. We begin with an overview of data concerning all SEC enforcement actions from 1997 to 2002. We find that the volume of SEC enforcement proceedings is relatively modest. We next examine the scope of the recently enacted Fair Fund provision that authorizes the SEC to designate civil penalties it recovers from defendants to benefit defrauded private investors. We conclude that this provision offers only limited potential relief for private investors. We complete this Part of the Article with an analysis of the serious resource limitations faced by the SEC. The second portion of the Article contains an empirical analysis of the determinants of SEC enforcement actions and the overlap of private fraud suits and SEC enforcement proceedings. Using bivariate analysis, we find that (1) private suits with parallel SEC actions settle for significantly more than private suits without such proceedings; (2) SEC enforcement actions target significantly smaller companies than private actions alone; (3) private cases with parallel SEC actions take substantially less time to settle than other private cases; and (4) private cases with parallel SEC actions have significantly longer class periods than other private actions. Finally, we create a model for estimating damages to compare settlement ratios in cases with parallel SEC actions to those in private actions. We find that one-fourth of all the private class action settlements occurring in suits that yield less than 10 percent of provable losses are settled for less than 2 percent of provable losses, but that there are no private actions with parallel SEC suits with such small settlements. In the final Part of the Article, we conduct a multivariate regression analysis of the determinants of when SEC enforcement actions are filed. We find that the most highly significant determinant of SEC actions is financial distress. Estimated losses do not appear to be a statistically significant factor in the SEC\u27s decision to file these suits

Transistor-Like Behavior of a Bose-Einstein Condensate in a Triple Well Potential

In the last several years considerable efforts have been devoted to developing Bose-Einstein Condensate (BEC)-based devices for applications such as fundamental research, precision measurements and integrated atom optics. Such devices capable of complex functionality can be designed from simpler building blocks as is done in microelectronics. One of the most important components of microelectronics is a transistor. We demonstrate that Bose-Einstein condensate in a three well potential structure where the tunneling of atoms between two wells is controlled by the population in the third, shows behavior similar to that of an electronic field effect transistor. Namely, it exhibits switching and both absolute and differential gain. The role of quantum fluctuations is analyzed, estimates of switching time and parameters for the potential are presented.Comment: 12 pages, 12 figure