The Use of Discordant MZ Twins to Generate Hypotheses regarding Non-shared Environmental Influence on Anxiety in Middle Childhood

Non‐shared environmental influence (NSE) has been found to account for around 50 percent of anxiety variance, but specific NSE factors have not been identified. Discordant monozygotic (MZ) twins can be used to generate relevant hypotheses because MZ discordance can be caused by NSE, but not by genes or shared environment. Of 1590 MZ pairs teacher rated for anxiety at the age of seven, we selected the most discordant 19 pairs and conducted interviews with them and their mothers. In explaining discordant anxiety, the mothers emphasised negative school experiences, comparisons within the twin relationship, and illness and accidents. During the maternal interviews neonatal life events, parent–child relationships and peer rejection also emerged as potential NSE sources.     

Women's employment patterns during early parenthood: A group‐based trajectory analysis

Research on women's employment and parenthood frequently focuses on the correlates and consequences of decisions at a particular time, such as a birth. This article applies a group‐based trajectory method to examine women's employment trajectories across the period of early parenthood using the National Longitudinal Survey of Youth 1979 (N= 2,093). We find that throughout early parenthood, women exhibit significant movement into and out of the labor force. Factors that typically predict women's employment status, such as age at first birth and education, are also good predictors of women's employment patterns. We discuss the implications of these findings for future research, particularly on the use of a static measure of women's or couples’ employment status.     

THE PATRIARCHAL BARGAIN AND INTERGENERATIONAL CORESIDENCE IN EGYPT

This article examines variation in intergenerational coresidence among older women and men in Egypt using data from the WHO Collaborative Study on the Social and Health Aspects of Aging . Residence with sons and daughters-in-law is preferred, although residence with daughters and sons-in-law occurs because patrilocal endogamy is common. Whereas residence with sons and daughters declines with age among men, it declines then increases with age among women. Residence with sons-in-law is uncommon among older men and becomes more frequent with age among older women. Findings support the idea that women's exchange of kin-keeping tasks for protection from kin gives older women greater access to normative and alternative forms of intergenerational coresidence, even after accounting for differences in need.     

Premature birth and the changing composition of newborn infectious disease mortality: Reconsidering “exogenous” mortality

Linked death and birth records from San Antonio, Texas reveal that infectious infant mortality is increasingly a function of premature birth and low birth weight. Between 1935 and 1944, 4% of infectious infant deaths had associated causes involving prematurity and related conditions; by 1980, 25% of infectious infant deaths involved prematurity and more than 40% of those infants weighed less than 2,500 grams. The shift in birth-weight composition results almost entirely from an increase in very low-weight births. Under conditions of advanced perinatal technology, infectious infant mortality should no longer be viewed as wholly exogenous. These findings further undermine the contemporary relevance of the exogenous-endogenous distinction.     

Sex differences in observers' reactions to a nurse's use of touch

We tested the notion that male and female observers would have different reactions to the use of touch by a nurse towards a patient in a hospital situation. If males are socialized to favor autonomy and independence and females to favor nurturance and caring, it was assumed that male subjects would rate a nurse as less supportive and competent if a nurse touched a patient. The results (based on reactions to photographs manipulating the level of physical contact that occurred between a nurse and a patient) were generally consistent with these predictions. While the subjects' sex moderated reactions to the nurse-initiated touch, there was an overall pattern for observers to react more favorably to the nurse who used touch compared to no touch in interacting with a patient. The results suggest that nurses and health professionals who use touch in interacting with patients may be judged in part by the attitudes of males and females about the use of touch.     

When Does a Retailer's Advance Selling Capability Benefit Manufacturer,Retailer, or Both?

Advance selling (AS) from a retailer to consumers is commonly observed in practice. With an AS capability, a retailer has the option to sell in advance or not. Having the AS option seems to increase flexibility and thus profit for a retailer. However, we show that the AS option can hurt the retailer's profit as well as supply chain performance. We identify two thresholds for a product's marginal production cost. A retailer's AS option benefits both the manufacturer and retailer when the marginal production cost is high, that is, above both thresholds. It benefits the manufacturer but hurts the retailer when the marginal production cost is moderate, that is, between the two thresholds. The result is ambiguous when the marginal production cost is low, that is, below both thresholds. We find that consumer valuation uncertainty under AS is the key driving force for the surprising result that having the retailer's AS option can hurt the retailer. When compared to the scenario where the retailer does not have the AS option, we find that the manufacturer's optimal wholesale price weakly decreases under the retailer's AS option if the marginal production cost is high. The statement is reversed if the marginal production cost is moderate or low.     

Some properties of the dirichlet-multinomial distribution and its use in prior elicitation

Two results on the unimodality of the Dirichlet-multinomial distribution are proved, and a further result is alos proved on the identifiability of mixtures of multinomial distributions. These properties are used in developing a method for eliciting a Dirchlet prior distribution. The elicitation method is based on the mode, and region around the mode, of the Dirichlet-multinomial predictive distribution.