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51.
The performance of contrarian, or value strategies – those that invest in stocks that have low market value relative to a measure of their fundamentals – continues to attract attention from researchers and practitioners alike. While there is much extant evidence on the profitability of value strategies, however, most of this evidence pertains to the US. In this paper, we provide a detailed characterisation of value strategies using data on UK stocks for the period 1975 to 1998. We first undertake simple one-way and two-way classifications of stocks in which value is defined using both past performance and expected future performance. Using sales growth as a proxy for past performance and book-to-market, earnings yield and cash flow yield as measures of expected future performance, we find that that stocks that have both poor past performance and low expected future performance have significantly higher returns than those that have either good past performance or good expected future performance. Allowing for size effects in returns reduces the value premium but it nevertheless remains significant. We go on to explore whether the profitability of value strategies in the UK can be explained using the three factor model of Fama and French (1996). Broadly consistent with the results for the US, we find that using the one-way classification the excess returns to almost all value strategies can be explained by their loading on the market, book-to-market and size factors. However, in contrast with the US, using the two-way classification there are excess returns to value strategies based on book-to-market and sales growth, even after controlling for their loading on the market, book-to-market and size factors.  相似文献   
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Most foodstuffs have quality attributes that are difficult to determine prior to purchase. Thus quality assurance is an inherent problem in food exporting. Private quality assurance can succeed if exporters can credibly signal that they have much to lose from cessation of purchases. If exporters do not provide credible quality signals, and foreign importers judge food quality according to country of origin, honest exporters can suffer negative spillovers from others' cheating under either government or private quality assurance. For both economic and political reasons, the best choice between government and private quality assurance will differ between foods and importing countries.  相似文献   
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We investigate firms that stop providing earnings guidance (“stoppers”) either by publicly announcing their decision (“announcers”) or doing so quietly (“quiet stoppers”). Relative to firms that continue guiding, stoppers have poorer prior performance, more uncertain operating environments, and fewer informed investors. Announcers commit to non-disclosure because they (i) do not expect to report future good news or (ii) have lower incentives to guide due to the presence of long-term investors. The three-day return around the announcement is negative. Stoppers subsequently experience increases in analyst forecast dispersion and decreases in forecast accuracy but no change in return volatility or analyst following.  相似文献   
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Two distinguished Morgan Stanley “alumni” discuss how their management of risk and uncertainty has not only preserved but increased the profitability of their businesses. In both cases—one involving a commodities trading operation and the other a long‐short hedge fund—the key has been to find cost‐effective ways to “cut off the left tails” of the distribution by avoiding naked long or short positions and creating option‐like payoffs with limited downside. In the case of the hedge fund, the combination of longs and shorts with the use of other risk‐reducing strategies has enabled the fund's managers to produce twice the market's returns with only half the volatility (and only one losing year) during the 18‐year life of the fund. In the case of the commodities trading operation, the strategy is described as combining ownership of physical assets with the use of option pricing models to create what amount to “long gamma positions in the asset” that “produce payoffs regardless of whether the asset goes up or down in value.”  相似文献   
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Traditionally, logistics design is driven by a need to reduce costs and improve customer service. Recently, the environmental concerns from transport have been increasingly discussed. The traffic levels and associated energy consumption are influenced by supply chain structure, modal split and vehicle utilization. This paper aims to assess the impact of the traditional cost optimization approach to strategic modelling on overall logistics costs and CO2 emissions by taking into account the supply chain structure (number of depots) and different freight vehicle utilization ratios (90%, 75% and 60%). The simulation model, based on a European case study from the automotive industry, considers strategic and operational level decisions simultaneously. The analysis shows that the optimum design based on costs does not necessary equate to an optimum solution for CO2 emissions, therefore there is a need to address economical and environmental objectives explicitly as part of the logistics design.  相似文献   
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Background: Validation of overall survival (OS) extrapolations of immune-checkpoint inhibitors (ICIs) during the National Institute for Health and Care Excellence (NICE) Single Technology Assessment (STA) process is limited due to data still maturing at the time of submission. Inaccurate extrapolation may lead to inappropriate decision-making. The availability of more mature trial data facilitates a retrospective analysis of the plausibility and validity of initial extrapolations. This study compares these extrapolations to subsequently available longer-term data.

Methods: A systematic search of completed NICE appraisals of ICIs from March 2000 to December 2017 was performed. A targeted search was also undertaken to procure published OS data from the pivotal clinical trials for each identified STA made available post-submission to NICE. Initial Kaplan-Meier curves and associated extrapolations from NICE documentation were extracted to compare the accuracy of OS projections versus the most mature data.

Results: The review identified 11 STAs, of which 10 provided OS data upon submission to NICE. The extrapolations undertaken considered parametric or piecewise survival models. Additional data cut-offs provided a mean of 18 months of OS beyond the end of the original data. Initial extrapolations typically under-estimated OS from the most mature data cut-off by 0.4–2.7%, depending on the choice of assessment method and use of the manufacturer- or ERG-preferred extrapolation.

Conclusion: Long-term extrapolation of OS is required for NICE STAs based on initial immature OS data. The results of this study demonstrate that the initial OS extrapolations employed by manufacturers and ERGs generally predicted OS reasonably well when compared to more mature data (when available), although on average they appeared to underestimate OS. This review and validation shows that, while the choice of OS extrapolation is uncertain, the methods adopted are generally aligned with later-published follow-up data and appear appropriate for informing HTA decisions.  相似文献   

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