1,217 research outputs found

    Verification of Citations: Fawlty Towers of Knowledge?

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    The prevalence of faulty citations impedes the growth of scientific knowledge. Faulty citations include omissions of relevant papers, incorrect references, and quotation errors that misreport findings. We discuss key studies in these areas. We then examine citations to Estimating nonresponse bias in mail surveys, one of the most frequently cited papers from the Journal of Marketing Research, as an exploratory study to illustrate these issues. This paper is especially useful in testing for quotation errors because it provides specific operational recommendations on adjusting for nonresponse bias; therefore, it allows us to determine whether the citing papers properly used the findings. By any number of measures, those doing survey research fail to cite this paper and, presumably, make inadequate adjustments for nonresponse bias. Furthermore, even when the paper was cited, 49 of the 50 studies that we examined reported its findings improperly. The inappropriate use of statistical-significance testing led researchers to conclude that nonresponse bias was not present in 76 percent of the studies in our sample. Only one of the studies in the sample made any adjustment for it. Judging from the original paper, we estimate that the study researchers should have predicted nonresponse bias and adjusted for 148 variables. In this case, the faulty citations seem to have arisen either because the authors did not read the original paper or because they did not fully understand its implications. To address the problem of omissions, we recommend that journals include a section on their websites to list all relevant papers that have been overlooked and show how the omitted paper relates to the published paper. In general, authors should routinely verify the accuracy of their sources by reading the cited papers. For substantive findings, they should attempt to contact the authors for confirmation or clarification of the results and methods. This would also provide them with the opportunity to enquire about other relevant references. Journal editors should require that authors sign statements that they have read the cited papers and, when appropriate, have attempted to verify the citations.citation errors; evidence-based research; nonresponse bias; quotation errors; surveys

    An integrated approach for evaluating the effectiveness of landslide risk reduction in unplanned communities in the Caribbean

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    Despite the recognition of the need for mitigation approaches to landslide risk in developing countries, the delivery of ‘on-the-ground’ measures is rarely undertaken. With respect to other ‘natural’ hazards it is widely reported that mitigation can pay. However, the lack of such an evidence-base in relation to landslides in developing countries hinders advocacy amongst decision makers for expenditure on ex-ante measures. This research addresses these limitations directly by developing and applying an integrated risk assessment and cost-benefit analysis of physical landslide mitigation measures implemented in an unplanned community in the Eastern Caribbean. In order to quantify the level of landslide risk reduction achieved, landslide hazard and vulnerability were modelled (before and after the intervention) and project costs, direct and indirect benefits were monetised. It is shown that the probability of landslide occurrence has been substantially reduced by implementing surface-water drainage measures, and that the benefits of the project outweigh the costs by a ratio of 2.7 to 1. This paper adds to the evidence base that ‘mitigation pays’ with respect to landslide risk in the most vulnerable communities – thus strengthening the argument for ex-ante measures. This integrated project evaluation methodology should be suitable for adoption as part of the community-based landslide mitigation project cycle, and it is hoped that this resource, and the results of this study, will stimulate further such programmes.Landslide modelling, Risk assessment, Cost Benefit Analysis, Developing countries, Community

    Forecasting new product trial with analogous series

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    types: ArticleNOTICE: this is the author’s version of a work that was accepted for publication in Journal of Business Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Business Research, 2015. doi:10.1016/j.jbusres.2015.03.032This study develops a simple method for forecasting consumer trial for national product launches. The number of consumers who try a brand in its first year on the market is accurately predicted from the number trying the brand in the first thirteen weeks following launch. No information about the specific category or marketing activities is required– just a simple multiplier computed from analogous series in other markets. These analogues provide an empirical generalization that can be easily applied by practicing managers to track and forecast the success of new brand launches. When subject to an out-of-sample test involving 34 fresh data sets, the analogues demonstrated 43 percent reduction in Mean Absolute Percentage Error compared to the most accurate marketing science model

    The relationship between household life cycle and brand loyalty

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    types: ArticleThis research investigates changes in brand loyalty as households pass from one stage of the household life cycle to another. Analysing 45 brands in three consumer product categories in the UK, we find that the changes follow a U shape pattern. Brand loyalty declines as households shift from the young single stage to the young couple and the young family stage, remains relatively lower through the older family stage, and then increases at the post family and older single stages

    Conductances, transference numbers, and activity coefficients of chlorides of some high atomic rare earths in aqueous solution

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    The conductances, transference numbers, and activity coefficients of lanthanum chloride, samaric chloride, europic chloride, and ytterbic chloride were determined in order to test the present theories of electrolytic solutions as well as to make available accurate data on these useful properties for the above rare earth chlorides

    Varying the Divergence of Multiple Parallel Laser Beams

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    A provision for controlled variation of the divergence of a laser beam or of multiple parallel laser beams has been incorporated into the design of a conceptual free-space optical-communication station from which the transmitted laser beam(s) would be launched via a telescope. The original purpose to be served by this provision was to enable optimization, under various atmospheric optical conditions, of the divergence of a laser beam or beams transmitted from a ground station to a spacecraft

    Pointing Reference Scheme for Free-Space Optical Communications Systems

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    A scheme is proposed for referencing the propagation direction of the transmit laser signal in pointing a free-space optical communications terminal. This recently developed scheme enables the use of low-cost, commercial silicon-based sensors for tracking the direction of the transmit laser, regardless of the transmit wavelength. Compared with previous methods, the scheme offers some advantages of less mechanical and optical complexity and avoids expensive and exotic sensor technologies. In free-space optical communications, the transmit beam must be accurately pointed toward the receiver in order to maintain the communication link. The current approaches to achieve this function call for part of the transmit beam to be split off and projected onto an optical sensor used to infer the pointed direction. This requires that the optical sensor be sensitive to the wavelength of the transmit laser. If a different transmit wavelength is desired, for example to obtain a source capable of higher data rates, this can become quite impractical because of the unavailability or inefficiency of sensors at these wavelengths. The innovation proposed here decouples this requirement by allowing any transmit wavelength to be used with any sensor. We have applied this idea to a particular system that transmits at the standard telecommunication wavelength of 1,550 nm and uses a silicon-based sensor, sensitive from 0.5 to 1.0 micrometers, to determine the pointing direction. The scheme shown in the figure involves integrating a low-power 980-nm reference or boresight laser beam coupled to the 1,550-nm transmit beam via a wavelength-division-multiplexed fiber coupler. Both of these signals propagate through the optical fiber where they achieve an extremely high level of co-alignment before they are launched into the telescope. The telescope uses a dichroic beam splitter to reflect the 980- nm beam onto the silicon image sensor (a quad detector, charge-coupled device, or active-pixel-sensor array) while the 1,550- nm signal beam is transmitted through the optical assembly toward the remotely located receiver. Since the 980-nm reference signal originates from the same single-mode fiber-coupled source as the transmit signal, its position on the sensor is used to accurately determine the propagation direction of the transmit signal. The optics are considerably simpler in the proposed scheme due to the use of a single aperture for transmitting and receiving. Moreover, the issue of mechanical misalignment does not arise because the reference signal and transmitted laser beams are inherently co-aligned. The beam quality of the 980-nm reference signal used for tracking is required to be circularly symmetric and stable at the tracking-plane sensor array in order to minimize error in the centroiding algorithm of the pointing system. However, since the transmit signal is delivered through a fiber that supports a single mode at 1,550 nm, propagation of higher order 980-nm modes is possible. Preliminary analysis shows that the overall mode profile is dominated by the fundamental mode, giving a near symmetric profile. The instability of the mode was also measured and found to be negligible in comparison to the other error contributions in the centroid position on the sensor array

    A new theorem for optimizing the advertising budget

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    This paper reports a new theorem and proof for optimizing the advertising budget. The theorem is that the optimal rate of advertising is equal to gross profit multiplied by advertising elasticity. This does not involve a ratio of elasticities, and so is an advance on the Dorfman-Steiner theorem that has dominated this topic for the last 50 years. The elegant nature of the proof makes it especially suitable for managerial economics textbooks. The simple nature of the theorem means that it is easily adopted, by both large and small businesses, in place of heuristics such as industry advertising to sales ratios. From meta-analysis, the mean advertising elasticity is .11. Therefore, in the absence of any other information, companies should spend 11% of gross profit on advertising

    How to grow a brand: retain or acquire customers?

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    Journal ArticleWhile customer acquisition is clearly important for new brands, mature brands are often said to rely on defection management for maintenance and growth. Yet the theory to support this approach has been subject to very little empirical investigation. How do brands actually increase the size of their customer base? Through superior acquisition or by reducing customer defection? Or some mixture of both? Conversely, do brands decline through deficient acquisition or excessive defection? This work analyzes changes in ‘first brand loyal’ customers to answer these questions, using a combination of panel data on the prescribing behavior of doctors and a cross-sectional tracking survey for residential finance. This study is the first research to compare defection and acquisition against stochastic benchmarks for customer churn under stationary conditions. The results are surprising: for both growth and decline, unusual acquisition plays a stronger role than unusual defection. This finding demonstrates that acquisition has been under-rated in the past, and implies that prospect management is at least as important as defection reduction. A simulation shows that unusual acquisition also accounts for far more variation in profit than does unusual defection.n/

    A new theorem for optimizing the advertising budget

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    This paper reports a new theorem and proof for optimizing the advertising budget. The theorem is that the optimal rate of advertising is equal to gross profit multiplied by advertising elasticity. This does not involve a ratio of elasticities, and so is an advance on the Dorfman-Steiner theorem that has dominated this topic for the last 50 years. The elegant nature of the proof makes it especially suitable for managerial economics textbooks. The simple nature of the theorem means that it is easily adopted, by both large and small businesses, in place of heuristics such as industry advertising to sales ratios. From meta-analysis, the mean advertising elasticity is .11. Therefore, in the absence of any other information, companies should spend 11% of gross profit on advertising
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