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191.
We consider a retailer’s decision of whether to develop an internally produced, private label version of a national brand and the role that this decision plays in coordinating the supply chain. Our model assumes that the perceived quality of the private label is lower than that of the national brand, and we allow for the two products to have different marginal costs. We further allow for a fixed development cost that the retailer must incur to develop private label capability, and distinguish two types of private labels depending upon whether they would or would not be developed as product line extensions by a vertically integrated supply chain. We refer to these two types as first‐best (FB) and non‐first‐best (NFB) product line extensions, respectively. When the private label can be characterized as a NFB product line extension, its development creates adverse cannibalization effects, yet it also helps to mitigate the effects of double marginalization with respect to the national brand. We characterize the conditions under which the retailer will develop private label capability, and distinguish among the conditions under which this is either beneficial or detrimental to the overall performance of the supply chain. 相似文献
192.
193.
Preliminary Development and Validation of the Social and Emotional Health Survey for Secondary School Students 总被引:1,自引:0,他引:1
Michael J. Furlong Sukkyung You Tyler L. Renshaw Douglas C. Smith Meagan D. O’Malley 《Social indicators research》2014,117(3):1011-1032
This study reports on the preliminary development and validation of the Social and Emotional Health Survey (SEHS) with a sample of 4,189 (51 % female) California students in Grades 8, 10, and 12. The SEHS was designed to measure the psychological building blocks of adolescents’ positive mental health and is operationalized in the present study by a theoretical model comprised of 12 measured indicators that form four first-order domains (belief-in-self, belief-in-others, emotional competence, and engaged living) that, in turn, contribute to one underlying, second-order meta-construct called covitality. This study was the first to investigate the validity and utility of the adolescent covitality construct, which is conceptualized as the synergistic effect of positive mental health resulting from the interplay among multiple positive-psychological building blocks. Findings from confirmatory factor analyses, invariance analysis, and latent means testing all supported the theoretical model underlying the SEHS, indicating that the second-order covitality model was the best fit for both males and females. Results from a path-modeling analysis indicated that covitality was a strong predictor of students’ subjective well-being (operationalized as a composite of life satisfaction, positive affect, and negative affect), and findings from additional concurrent validity analyses indicated that adolescents’ covitality level was significantly associated with self-reported academic achievement, perceptions of school safety, substance use, and experiences of depressive symptoms. Implications for theory, practice, and future research are discussed. 相似文献
194.
Projections of total population have been evaluated extensively, but few studies have investigated the performance of projections by age. Of those that did, most focused on projections for countries or other large areas. In this article, we evaluate projections by age for Florida and its counties, as produced and published between 1996 and 2010 by the Bureau of Economic and Business Research at the University of Florida. We first compare the precision and bias of projections of total population with the precision and bias of projections by age, at both the state and county levels. This is followed by a more detailed examination of county-level projection errors for individual age groups, first in the aggregate and then disaggregated by sex and population size. The second part of the analysis focuses on a number of adjustments that were implemented in projections published in 2006 and 2009. Intended to improve accuracy, these adjustments involved updates to the base population, fertility rates, and survival rates. We compare the accuracy of projections incorporating these adjustments with the accuracy of projections excluding them. We believe this study offers a unique opportunity to examine a variety of characteristics regarding the forecast accuracy of small-area population projections by age. 相似文献
195.
Objective. This research examines the migration behavior of the elderly, recognizing that the older and younger elderly may make different decisions and have different consequences for the states in which they live. Methods. Using U.S. Census migration flow data, we describe the movements of the younger and older elderly. Our econometric analysis brings together the wisdom of elderly migration research that focuses on motives (amenity vs. return/assistance) and the Tiebout‐related research that considers the effects of policy. Results. We find that all elderly age groups avoid moving to states with high estate/inheritance/gift taxes, although the effect weakens with age. Likewise, the younger elderly appear to be “shopping around” for destinations with a temperate climate and favorable government policies regarding income taxes and welfare spending, whereas the older elderly are more likely to be “driven out” of their origin state by a high cost of living and income and property taxes. Conclusions. Our findings suggest that both the patterns of migration and the factors that affect migration decisions differ between the younger and older elderly. 相似文献
196.
197.
Tom W. Smith 《Social science research》2002,31(4)
Different methods of measuring inter-racial contacts produce large differences in the level of the same. Experiments conducted on the 1998 General Social Survey indicate that estimates of how many people have inter-racial friends are much higher when a direct question is asked, intermediate when a three-step procedure is used, and the least when a name-generator, network approach is used. Cognitive and social desirability reasons for these effects are discussed. 相似文献
198.
The growing relative number, the improved economic well-being, and the migration of elderly retirees is not only reshaping the social and economic structure of many areas, it is also modifying both long-term and short-run patterns of economic growth. Transfer payments and property incomes, two of the most important source of elderly income, have been among the leading sources of national income growth over the past several decades. Unlike most labor-related industry sources of earnings, the level of transfer payments and property incomes received by the residents of the region is not directly dependent upon local economic activity. Consequently, as transfer payments and property incomes of elderly retirees become increasingly important sources of income and purchasing power within a region, they also can alter regional short-run cyclical patterns of income growth. This article examines the pattern of growth of transfer payments and property incomes in the context of national economic cycles, and explores the implication of those findings on metropolitan and nonmetropolitan Nevada economies. 相似文献
199.
E.J. Smith 《统计学通讯:理论与方法》2013,42(10):223-230
An experimenter in the field of cloud seeding describes aspects of experiments which he would like statisticians to take into account and suggects Problems which he would like statisficians solve. 相似文献
200.
In pest risk assessment it is frequently necessary to make management decisions regarding emerging threats under severe uncertainty. Although risk maps provide useful decision support for invasive alien species, they rarely address knowledge gaps associated with the underlying risk model or how they may change the risk estimates. Failure to recognize uncertainty leads to risk‐ignorant decisions and miscalculation of expected impacts as well as the costs required to minimize these impacts. Here we use the information gap concept to evaluate the robustness of risk maps to uncertainties in key assumptions about an invading organism. We generate risk maps with a spatial model of invasion that simulates potential entries of an invasive pest via international marine shipments, their spread through a landscape, and establishment on a susceptible host. In particular, we focus on the question of how much uncertainty in risk model assumptions can be tolerated before the risk map loses its value. We outline this approach with an example of a forest pest recently detected in North America, Sirex noctilio Fabricius. The results provide a spatial representation of the robustness of predictions of S. noctilio invasion risk to uncertainty and show major geographic hotspots where the consideration of uncertainty in model parameters may change management decisions about a new invasive pest. We then illustrate how the dependency between the extent of uncertainties and the degree of robustness of a risk map can be used to select a surveillance network design that is most robust to knowledge gaps about the pest. 相似文献