8,489 research outputs found
Texture control in a pseudospin Bose-Einstein condensate
We describe a wavefunction engineering approach to the formation of textures
in a two-component nonrotated Bose-Einstein condensate. By controlling the
phases of wavepackets that combine in a three-wave interference process, a
ballistically-expanding regular lattice-texture is generated, in which the
phases determine the component textures. A particular example is presented of a
lattice-texture composed of half-quantum vortices and spin-2 textures. We
demonstrate the lattice formation with numerical simulations of a viable
experiment, identifying the textures and relating their locations to a linear
theory of wavepacket interference.Comment: 4 pages, 5 figures, REVTeX4-
Economic Applications of an Electronic Clinical Database for Nurse Practitioner Students
To describe the development of a Web-based clinical database that incorporates the standardized nursing languages (SNLs) used by nurse practitioner students, describe outcomes relative to the SNLs, and discuss economic aspects of outcome data. METHODS . A mix of retrospective and prospective data of all outcomes for several cohorts (95 students, 17,193 records) comprised the data set. FINDINGS . There is wide variation in use of SNLs as well as terminologies from other disciplines. The economic impact of patient encounters could be substantial. CONCLUSIONS . A Web-based clinical log provides an opportunity for NP students to collect and analyze data on clinical encounters. Considerable resources must be invested in order to expand the use and sophistication of eClinicaLog.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73941/1/j.1744-618X.2004.tb00003.x.pd
Estimating Firm-Level Demand at a Price Comparison Site: Accounting for Shoppers and the Number of Competitors
Clearinghouse models of online pricing---such as Varian (1980), Rosenthal (1980), Narasimhan (1988), and Baye-Morgan (2001)---view a price comparison site as an 'information clearinghouse' where shoppers and loyals obtain price and product information to make online purchases. These models predict that the responsiveness of a firm's demand to a change in its price depends on the number of sellers and whether the price change results in the firm charging the lowest price in the market. Using a unique firm-level dataset from Kelkoo.com (Yahoo!'s European price comparison site), we examine these predictions by providing estimates of the demand for PDAs. Our results indicate that the number of competing sellers and both the firm's location on the screen and relative ranking in the list of prices are important determinants of an online retailer's demand. We find that an online monopolist faces an elasticity of demand of about -2, while sellers competing against 10 other sellers face an elasticity of about -6. We also find empirical evidence of a discontinuous jump in a firm's demand as its price declines from the second-lowest to the lowest price. Our estimates suggest that about 13% of the consumers at Kelkoo are 'shoppers' who purchase from the seller offering the lowest price.Internet, Price Dispersion, Advertising
Clicks, Discontinuities, and Firm Demand Online
The market values of online platforms, such as Yahoo, stem from their ability to monetize the clicks they generate for firms advertising on their sites. We exploit a unique dataset on clicks from one of Yahoo's price comparison sites to estimate the determinants of clicks received by online retailers. We find that a firm enjoys a 60% jump in its clicks when it offers the lowest price at the site. This discontinuity is consistent with a variety of models that have been used to rationalize the price dispersion observed in online markets. We also show that one may use estimates of the determinants of a firm's clicks to obtain bounds on its underlying demand parameters, including own- and cross-price elasticities. Our results have potentially significant ramifications for online retailers, platforms, and policymakers: Failure to account for discontinuities distorts parameter estimates by 50 to 100 percent.
Did the Euro Foster Online Price Competition? Evidence from an International Price Comparison Site
We study the impact of the Euro on prices charged by online retailers within the EU. Our data spans the period before and after the Euro was introduced, covers a variety of products, and includes countries inside and outside of the Eurozone. After controlling for cost, demand, and market structure effects, we show that the pure Euro changeover effect is to raise average prices in the Eurozone by 3% and average minimum prices by 7%. Finally, we develop a model of online pricing in the context of currency unions, and show that these price patterns are broadly consistent with clearinghouse models.Price competition, internet
Rivals’ Reactions to Mergers and Acquisitions
Mergers and acquisitions research has principally focused on attributes of the acquiring firm and post-acquisition outcomes. To extend our knowledge, we focus on external factors, in particular rival responses, and explore when and how rivals respond to their competitor’s acquisitions. Leveraging the awareness–motivation–capability framework, we predict and find evidence that a rival’s dependence on markets in common with the acquirer, resource similarity between rival and acquirer, and a rival’s organizational slack increase the volume and, in some cases, also the complexity of a rival’s competitive actions following an acquisition. Furthermore, the type of acquisition positively moderates some of these relationships. The results extend our understanding of the influence of mergers and acquisitions on competitive dynamics in the marketplace
The Impact of Information Overload on the Capital Jury\u27s Ability to Assess Aggravating and Mitigating Factors
Since 1976, the U.S. Supreme Court has required that death penalty regimes meet two requirements. First, in order to minimize arbitrariness in the imposition of the death penalty, states must reserve capital punishment to a narrow class of offenders, those most deserving of death. States have done so by requiring that the prosecution prove at least one aggravating factor, i.e., some circumstance that separates the capital defendant on trial from those ineligible to be executed. Second, states must allow for individualization in sentencing by permitting the defendant to introduce mitigating evidence in order to persuade the jury that he is undeserving of death. The outcome has been that the penalty phase of the typical capital trial results in a flood of information from both prosecution and defense, much of it having little to do with the crime itself, through which the jury must wade. Whatever else may be said about our current death penalty jurisprudence, this flood of aggravating and mitigating evidence implicates the potential for information overload on the part of the capital jury. The concept of information overloadessentially, that too much information presented to a decision maker can result in sub-optimal decision making-has been widely explored in the marketing area. A few scholars have written on the potential impact of this phenomenon on consumer law and securities regulation. But until now, none has written on the potential impact of information overload on the capital jury. The sheer amount of information presented at the penalty phase of a capital trial likely exceeds many jurors\u27 capacities to process that information. In addition, the novelty, complexity, ambiguity, and intensity of the decision to be made virtually assure that a significant number of capital jurors experience information overload. Jurors under such a constraint face two choices. First, they may satisfice, or reach a decision that is sub-optimal simply to end the decision-making process. Second, they may opt out, or abdicate their decision-making responsibilities to the otherjurors. Neither result is acceptable in the capital context. In order to ease the potential effects of information overload, death penalty jurisdictions, with the approval of the Supreme Court, should reduce the amount of information presented at the penalty phase of capital trials. One logical way of doing this is to limit aggravating and mitigating circumstances at the penalty-selection stage to those that reflect on the individual culpability of the offender for the crime of conviction. This would mean doing away with victim impact evidence, evidence of future dangerousness, and all other non-culpability related aggravating evidence. This limitation would also require a loosening of the current strictures the Supreme Court currently places on the states\u27 ability to limit the defendant\u27s presentation of mitigating evidence. States should be permitted to limit the defendant\u27s introduction of mitigating evidence to that which reflects on his culpability for the crime, broadly conceived, and the states should exercise that authority
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