Efficiency determinants in retail stores: a Bayesian framework

This paper analyzes the impact of vertical integration, age, geographic expansion, and low price strategy on the cost efficiency of retail stores. We test our hypotheses using the innovative Bayesian frontier methodology. The data involve a sample of Spanish retail stores that operate in a highly competitive and dynamic environment. From the results, it is clear that cost efficiency is higher for stores that have: longer years in business, stronger geographical presence, and lower price offerings. Vertical integration, on the other hand, is negatively related to efficiency. Further discussions of these findings and related managerial implications are provided in the paper.     

Skin color,sex, and educational attainment in the post-civil rights era

We assess the relationship between skin color and educational attainment for native-born non-Hispanic Black and White men and women, using data from the Coronary Artery Risk Development in Young Adults (CARDIA) Study. CARDIA is a medical cohort study with twenty years of social background data and a continuous measure of skin color, recorded as the percent of light reflected off skin. For Black men and women, we find a one-standard-deviation increase in skin lightness to be associated with a quarter-year increase in educational attainment. For White women, we find an association approximately equal in magnitude to that found for Black respondents, and the pattern of significance across educational transitions suggests that skin color for White women is not simply a proxy for family background. For White men, any relationship between skin color and attainment is not robust and, analyses suggest, might primarily reflect differences in family background. Findings suggest that discrimination on the basis of skin color may be less specific to race than previously thought.     

African American Stepfather–Stepchild Relationships,Marital Quality,and Mental Health

ABSTRACT

This study examined associations between stepfather–stepchild relationship quality, stepfathers’ depressive symptoms, and two aspects of marriage: marital quality and positive marital interactions. Marital quality was assessed in terms of commitment, trust, passionate and friendship-based love, and happiness. Marital interactions were assessed in terms of intimacy, shared activities, and verbal communication. Using data collected from 149 recently married African American stepfathers, structural equation modeling revealed that when stepfathers reported more positive relationships with their stepchildren, they also reported more positive marital quality and a higher frequency of positive marital interactions (relationship-solidifying activities), and that, in turn, was associated with stepfathers experiencing fewer depressive symptoms.     

Efficient reassembling of graphs,part 1: the linear case

The reassembling of a simple connected graph \(G = (V,E)\) is an abstraction of a problem arising in earlier studies of network analysis. Its simplest formulation is in two steps:

1. (1)
   We cut every edge of G into two halves, thus obtaining a collection of \(n = |\,V\,|\) one-vertex components, such that for every \(v\in V\) the one-vertex component \(\{ v \}\) has \({{degree}}_{}(v)\) half edges attached to it.
    
2. (2)
   We splice the two halves of every edge together, not of all the edges at once, but in some ordering \(\Theta \) of the edges that minimizes two measures that depend on the edge-boundary degrees of assembled components.
    

A component A is a subset of V and its edge-boundary degree is the number of edges in G with one endpoint in A and one endpoint in \(V-A\) (which is the same as the number of half edges attached to A after all edges with both endpoints in A have been spliced together). The maximum edge-boundary degree encountered during the reassembling process is what we call the \(\varvec{\alpha }\) -measure of the reassembling, and the sum of all edge-boundary degrees is its \(\varvec{\beta }\) -measure. The \(\alpha \)-optimization (resp. \(\beta \)-optimization) of the reassembling of G is to determine an order \(\Theta \) for splicing the edges that minimizes its \(\alpha \)-measure (resp. \(\beta \)-measure). There are different forms of reassembling, depending on restrictions and variations on the ordering \(\Theta \) of the edges. We consider only cases satisfying the condition that if an edge between disjoint components A and B is spliced, then all the edges between A and B are spliced at the same time. In this report, we examine the particular case of linear reassembling, which requires that the next edge to be spliced must be adjacent to an already spliced edge. We delay other forms of reassembling to follow-up reports. We prove that \(\alpha \)-optimization of linear reassembling and minimum-cutwidth linear arrangment (\(\mathrm{CutWidth}\)) are polynomially reducible to each other, and that \(\beta \)-optimization of linear reassembling and minimum-cost linear arrangement (\(\mathrm{MinArr}\)) are polynomially reducible to each other. The known NP-hardness of \(\mathrm{CutWidth}\) and \(\mathrm{MinArr}\) imply the NP-hardness of \(\alpha \)-optimization and \(\beta \)-optimization.

     

The transition to lower fertility in the West Bank and Gaza Strip: evidence from recent surveys

Using recent data from three national-level surveys conducted in 1995, 2000, and 2004, we provide evidence that Palestinian fertility rates in the West Bank and Gaza Strip, historically among the highest in the world, began to slow especially in the West Bank, but stalled in Gaza during the recent Intifada. The TFR in the early 2000s was 4.6 per woman, down from 6.2 a decade earlier. However, most of the decline in Gaza’s fertility appears to have taken place during the early 1990s, before the onset of the second Intifada. In Gaza, the TFR decreased from 7.4 to 5.7 during the 1990s, but changed only slightly to 5.6 during the second Intifada period. Surprisingly, contraceptive prevalence has not changed during these years, and the transition to lower fertility was mainly due to changes in nuptiality. Demand for children remains high, although there is evidence of unmet need for contraception. The continuing conflict and worsening economic situation provide clues to the persistence of high fertility among Palestinian women.

Dialogue under Occupation

This article critically examines the World Bank's report entitled The Other Half of Gender: Men's Issues in Development published in 2006. The Bank publication covers a range of topics on men and masculinities, and ultimately argues for ‘men-streaming’ development. Using an intersectional analysis, this article expands upon recent feminist scholarship in the field of Men and Development in order to take a closer look at race, culture and representation. In this article, I demonstrate how the World Bank's focus on the social construction of masculinities in the ‘men-streaming’ report places Third World men into a specific realm of visibility that renders them culpable for a wide range of development issues. In representing African men as homogenous, culturally inferior and individually culpable for the HIV/AIDS pandemic, in particular, the Bank's promotes ‘gender-adjustments’, which obscures the Bank's complicity in a variety of development disasters.     

Why is one choice different?

Let X_i be nonnegative independent random variables with finite expectations and . The value is what can be obtained by a “prophet”. A “mortal” on the other hand, may use k1 stopping rules t₁,…,t_k yielding a return E[max_i=1,…,kX_ti]. For nk the optimal return is where the supremum is over all stopping rules which stop by time n. The well known “prophet inequality” states that for all such X_i's and one choice and the constant “2” cannot be improved on for any n2. In contrast we show that for k=2 the best constant d satisfying for all such X_i's depends on n. On the way we obtain constants c_k such that .     

Bayesian and DEA efficiency modelling: an application to hospital foodservice operations

The significant impact of health foodservice operations on the total operational cost of the hospital sector has increased the need to improve the efficiency of these operations. Although important studies on the performance of foodservice operations have been published in various academic journals and industrial reports, the findings and implications remain simple and limited in scope and methodology. This paper investigates two popular methodologies in the efficiency literature: Bayesian “stochastic frontier analysis” (SFA) and “data envelopment analysis” (DEA). The paper discusses the statistical advantages of the Bayesian SFA and compares it with an extended DEA model. The results from a sample of 101 hospital foodservice operations show the existence of inefficiency in the sample, and indicate significant differences between the average efficiency generated by the Bayesian SFA and DEA models. The ranking of efficiency is, however, statistically independent of the methodologies.     

A Note on the Relationship Among Capacity,Pricing, and Inventory in a Make‐to‐Stock System

We address the simultaneous determination of pricing, production, and capacity investment decisions by a monopolistic firm in a multi‐period setting under demand uncertainty. We analyze the optimal decision with particular emphasis on the relationship between price and capacity. We consider models that allow for either bi‐directional price changes or models with markdowns only, and in the latter case we prove that capacity and price are strategic substitutes.     

In or out of sync? Concordance between parent and adolescent sleep varies by family context

Evidence suggests significant interrelations among parent and adolescent sleep (i.e., concordance). However, less is known regarding how parent–adolescent sleep concordance varies as a function of the family context. This study examined daily and average concordance between parent and adolescent sleep and explored adverse parenting and family functioning (e.g., cohesion, flexibility) as potential moderators. One hundred and twenty-four adolescents (M_age = 12.90) and their parents (93% mothers) wore actigraphy watches assessing sleep duration, efficiency, and midpoint across 1 week. Multilevel models indicated daily (within-family) concordance between parent and adolescent sleep duration and midpoint. Average (between-family) concordance was found for sleep midpoint only. Family flexibility was linked with greater daily concordance in sleep duration and midpoint, whereas adverse parenting predicted discordance in average sleep duration and efficiency.