The Prevalence of Uncorrected Refractive Errors in Adolescents Incarcerated in a Youth Detention Center

The purpose of this study was to determine the number of residents requiring corrective lenses in a youth detention center for juveniles from 12 to 18 years old over a 2-year period. A greater number of adolescents incarcerated for criminal activity in a detention center had uncorrected refractive errors (34.87 %) as compared to a comparable population in the public school system (22 %). The prevalence of significant refractive errors among incarcerated adolescents in this study is significantly higher than has been reported previously. The current study found a refractive error rate of almost 35 %. This difference can be explained by a number of factors in their social environments and identifies an area for potential intervention to reduce antisocial behavior in this population.     

Sourcing Strategy,Supplier Relationships and Firm Performance: An Empirical Investigation of UK Organizations

This article conceptualizes and empirically examines buyer–supplier relationships in respect of supply sourcing strategies, relationship characteristics and firm performance. Two sourcing strategies available to organizations are examined, critical and leverage, which in turn, influence the approach to managing the supplier relationship (arms‐length or collaborative). We argue that different relationship approaches are appropriate to achieving different performance outcomes. A structural equation model, using a sample of 142 manufacturing firms based in the United Kingdom, is used to test this hypothesized model. The results indicate that a critical sourcing strategy requires collaborative supplier relationships in order to achieve higher relationship and business outcomes, while leverage sourcing strategies have a direct impact on these same performance outcomes. In addition, a leverage strategy was associated with increased levels of supplier power, though this power was found not to have a significant effect on performance. Our study provides support for the importance of aligning sourcing strategies to particular supplier relationship approaches in order to improve firm performance. Managerial implications of these findings and future directions for research are then offered.     

The Effect of Socialization Mechanisms and Performance Measurement on Supplier Integration in New Product Development

This article examines the effect of socialization mechanisms and supplier performance measurement on the level of supplier integration in new product development and subsequent firm performance outcomes. Prior research has found socialization mechanisms and performance measures to be effective in managing supplier relationships, though research examining their impact within a product development context has been limited. Socialization mechanisms, such as supplier conferences and on‐site visits, help establish communication and information‐sharing routines necessary to achieve supplier integration in the product development process. Using performance measures to evaluate a supplier helps focus managerial attention on areas such as innovation and communication that are important to integration success. A structural equation model, using a sample of 142 manufacturing firms based in the United Kingdom, indicates that the level of supplier integration in new product development is positively influenced by socialization mechanisms and innovation‐focused measures of supplier performance, but not significantly associated with the use of communication measures. In turn, increased levels of supplier integration led to improvements in both collaboration outcomes and business performance. Socialization mechanisms were also found to have a direct effect on collaboration outcomes achieved by the firm. Managerial implications and future research directions are discussed.     

Profile upper Confidence Limits from Discrete Data

When the data are discrete, standard approximate confidence limits often have coverage well below nominal for some parameter values. While ad hoc adjustments may largely solve this problem for particular cases, Kabaila & Lloyd (1997) gave a more systematic method of adjustment which leads to tight upper limits, which have coverage which is never below nominal and are as small as possible within a particular class. However, their computation for all but the simplest models is infeasible. This paper suggests modifying tight upper limits by an initial replacement of the unknown nuisance parameter vector by its profile maximum likelihood estimator. While the resulting limits no longer possess the optimal properties of tight limits exactly, the paper presents both numerical and theoretical evidence that the resulting coverage function is close to optimal. Moreover these profile upper limits are much (possibly many orders of magnitude) easier to compute than tight upper limits.     

Evidence of fertility regulation among rural french villagers, 1749–1789

In this first part an econometric model describing the sequences of live births to individual couples is developed and estimated, using data for a sample of married women in rural French communes during the period 1749–1789. The main methodological objective is to devise a means of controlling for unobserved heterogeneities that result in the endogeneity of variables describing a couple's accumulated demographic experience. Without such controls it is not possible to secure unbiased estimates of responses to familial demographic events, such as the births and deaths of children. Such estimates are sought here as indirect indicators of the existence and nature of deliberate fertility control.Un modèle économétrique, décrivant la suite des naissances vivantes d'un couple donné, est développé et estimé dans cette première partie, en utilisant des données sur un échantillon de femmes mariées dans des communes rurales françaises durant la période 1749–1789. Le principal objectif méthodologique est de fournir un moyen de contrôler l'hétérogénéité non observée qui résulte de variables endogènes décrivant l'expérience cumulative d'un couple. Sans un tel contrôle il n'est pas possible d'obtenir des estimations sans biais de l'effet d'événements démographiques, tels que les naissances et les décès d'enfants. De tels estimateurs sont recherchés ici en vue de fournir des indications indirectes sur l'exercice et la nature d'une prévention des naissances délibérée.

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The second part of this article will be published in theEuropean Journal of Population, Vol. 5, no. 2, pp. 173–206.