Material planning with uncertain product quality†

Traditional material requirement planning (MRP) is a system procedure to determine input quantities and ordering times to meet a specified demand in a deterministic framework. A variety of modifications to MRP have been proposed to incorporate different forms of uncertainty in production systems. In this paper, wc consider the case where the uncertainty is due to quality variations in the production process, and we develop an approach which links material planning with quality variations and control.     

Stock Market Efficiency: An Institutional Approach

Arbitman examines a particular strand of current Russian pulp fiction that portrays the United States as the source of all Russia's contemporary misfortunes but relies heavily on the works of writers such as Tom Clancy and Robert Ludlum.     

Moments of order statistics from a non-overlapping mixture model with applications to truncated laplace distribution

We employ two different approaches to derive single and product moments of order statistics from a truncated Laplace distribution. A direct evaluation method establishes recurrence relations whereas the more general non-overlapping mixture model incorporates the truncated Laplace distribution as a special case. The results are thereafter applied to estimate location and scale parameters of such distributions.     

Applications of asymptotic confidence intervals with continuity corrections for asymmetric comparisons in noninferiority trials

A large‐sample problem of illustrating noninferiority of an experimental treatment over a referent treatment for binary outcomes is considered. The methods of illustrating noninferiority involve constructing the lower two‐sided confidence bound for the difference between binomial proportions corresponding to the experimental and referent treatments and comparing it with the negative value of the noninferiority margin. The three considered methods, Anbar, Falk–Koch, and Reduced Falk–Koch, handle the comparison in an asymmetric way, that is, only the referent proportion out of the two, experimental and referent, is directly involved in the expression for the variance of the difference between two sample proportions. Five continuity corrections (including zero) are considered with respect to each approach. The key properties of the corresponding methods are evaluated via simulations. First, the uncorrected two‐sided confidence intervals can, potentially, have smaller coverage probability than the nominal level even for moderately large sample sizes, for example, 150 per group. Next, the 15 testing methods are discussed in terms of their Type I error rate and power. In the settings with a relatively small referent proportion (about 0.4 or smaller), the Anbar approach with Yates’ continuity correction is recommended for balanced designs and the Falk–Koch method with Yates’ correction is recommended for unbalanced designs. For relatively moderate (about 0.6) and large (about 0.8 or greater) referent proportion, the uncorrected Reduced Falk–Koch method is recommended, although in this case, all methods tend to be over‐conservative. These results are expected to be used in the design stage of a noninferiority study when asymmetric comparisons are envisioned. Copyright © 2013 John Wiley & Sons, Ltd.     

Lessons in Democracy: America's Tenuous History with Immigrants

Taking an uncompromising stance on immigration enforcement, the Trump administration has been sharply criticized for its policies and racially coded rhetoric of immigrants as criminals or undesirables. Despite this criticism, the administration's policies fall in line with historically widespread, exclusionary, nativist and xenophobic attitudes towards immigrants. Much of the American immigrant story has been a tortuous struggle for equality, integration and civil rights. This essay takes a critical look at the complicated history of immigration policy during the last century, focusing on the social, economic and political forces that helped shape legislation.     

The adoption of women’s legislative caucuses worldwide

Recent decades have witnessed the rise, across a wide range of countries, of political institutions designed to promote gender equality and women’s political representation. Existing studies have shown how international diffusion processes have contributed to the adoption of two kinds of such institutions – gender mainstreaming and gender quotas. Mounting evidence suggests that institutional reforms within legislatures constitute the latest wave of gendered institutional reform. This article identifies and explains trends in the adoption of one kind of gender-focused parliamentary institution – women’s legislative caucuses (WLCs). We use a discrete time duration model to assess the effect of several factors on WLC establishment. While there is theoretical room to expect diffusion, structural and institutional variables to affect the likelihood of caucus adoption, we find the strongest empirical support for diffusion and institutional factors. A parliament’s likelihood of adopting a WLC rises when sub-regional peers have created WLCs, when women’s international non-governmental organizations are active in the country and when the country has implemented a gender quota. Understanding the factors that affect the adoption of gender-focused parliamentary institutions is critically important, we argue, since such bodies provide space to confront masculinized institutionalized rules and norms.     

Impact of subsidiaries' cross-border knowledge tacitness shared and social capital on MNCs' explorative and exploitative innovation capability

As subsidiaries' cross-border knowledge increases in tacitness, it becomes more difficult for subsidiaries to articulate and for multinational corporations' (MNCs') headquarters to integrate and apply. Herein, dynamic capabilities and social capital theory frame structural and relational social capital as capabilities that improve the productivity of subsidiaries' cross-border knowledge tacitness shared on MNCs' headquarters explorative and exploitative innovation capability. The hypotheses are tested on a data set consisting of survey data collected from 220 senior managers or executives at the headquarters of Taiwan-based MNCs. Interestingly, structural social capital between headquarters and subsidiaries strengthens the negative association between subsidiaries' cross-border knowledge tacitness shared and explorative innovation capability; relational social capital attenuates the negative association between subsidiaries' cross-border knowledge tacitness shared and both explorative and exploitative innovation capability. Stated differently, different types of social capital can facilitate (i.e., relational social capital) or impede (i.e., structural social capital) innovation capability when cross-border knowledge tacitness is high. The validity and managerial implications of these findings are explored through interviews with senior managers or executives of MNCs headquarters or subsidiaries. Theoretically, this study emphasizes the importance of understanding relationships between subsidiaries and MNCs' headquarters to understand the association between subsidiaries' resources and MNCs' headquarters innovation capability.     

Associations Between Early Life Stress, Child Maltreatment, and Pubertal Development Among Girls in Foster Care

The present study investigated pubertal development in girls with maltreatment histories (N = 100), assessed at four time points over 2 years beginning in the spring of their final year of elementary school. This sample is unique, in that participants were subject to an unusual level of environmental risk early in life and resided in foster care at the start of the study. Analyses replicated the previously established association between sexual abuse and earlier onset of maturation and earlier age at menarche. Physical abuse was related to a more rapid tempo of pubertal development across the period assessed. These results strengthen previous investigations of childhood maltreatment and puberty, highlighting the complexity and specificity of early life experiences for later development.     

Youth earnings and labour market volatility in Europe

The authors provide new evidence on youth earnings and labour market volatility, including flows into and out of employment, across Europe during the Great Recession. EU‐SILC data for the period 2004–13 reveal large disparities in volatility levels and trends across European countries. As expected, the Great Recession increased youth labour market volatility, offsetting the trends observed over the previous years of economic prosperity. A variance decomposition exercise points to greater exposure to worker turnover in southern Europe. Fixed effects regression on labour market institutions relates higher unemployment benefits and more stringent employment protection legislation to lower earnings and labour market volatility.     

Testing goodness of fit via nonparametric function estimation techniques

An overview is given of methodology for testing goodness of fit of parametric models using nonparametric function estimation techniques. The ideas are illustrated in two settings: the classical one-sample goodness-of-fit scenario and testing the goodness of fit of a polynomial regression model.