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.     

Evaluations of Women and Men Among Black and White College Students1

Rainwater's assertion that blacks have low self-evaluations because they receive more negative evaluations from other blacks than whites receive from other whites is challenged here by reference to Heiss and Owens evidence that negative self evaluation among blacks is limited to work-related traits. Substantial support was found for our major hypotheses that, compared to whites, (1) blacks would report more negative evaluation of “most men” but not of “most women” (since the provider role is traditionally ascribed primarily to men), and (2) the more negative evaluation of “most men” by blacks would be limited to work-related traits.     

Improving an upper bound on the size of k-regular induced subgraphs

This paper considers the NP-hard graph problem of determining a maximum cardinality subset of vertices inducing a k-regular subgraph. For any graph G, this maximum will be denoted by α _k (G). From a well known Motzkin-Straus result, a relationship is deduced between α _k (G) and the independence number α(G). Next, it is proved that the upper bounds υ _k (G) introduced in Cardoso et al. (J. Comb. Optim., 14, 455–463, 2007) can easily be computed from υ ₀(G), for any positive integer k. This relationship also allows one to present an alternative proof of the Hoffman bound extension introduced in the above paper. The paper continues with the introduction of a new upper bound on α _k (G) improving υ _k (G). Due to the difficulty of computing this improved bound, two methods are provided for approximating it. Finally, some computational experiments which were performed to compare all bounds studied are reported.     

Reverse logistics drivers: empirical evidence from a case study in an emerging economy

Academic and corporate interest in reverse logistics (RL) has risen considerably in recent years. In this context, the objective of this study was to identify the drivers that enable RL practice in an emerging economy. Firstly, international peer-reviewed publications on RL were used to develop a RL environment framework representing the main RL internal and external influences. Secondly, a case-based research was conducted in a large manufacturing company located in Southern Brazil. The results indicated that the most cited driver in the RL literature, the government and legislation, was not a main influence on the studied company. Environmental legislation is still limited in the country and struggles to provide incentives to increase materials recycling. An economic factor related to materials value recovery was also found to drive the backward flow. Finally, knowledge of the RL driving forces may support industries to better implement and manage reverse flows and to bridge the gap between existing and future solutions for reverse supply chains.     

The Early Medieval State: A Strategic-Relational Approach

The state is a contested concept in the historiography on early medieval societies. Debates have frequently revolved around its heuristic validity, but few scholars have addressed its broader theoretical implications. Those who have tend to reduce the state to its institutional features and privilege the role of the dominant groups in the analysis of state-building processes and the workings of the state. This paper contends that a richer conceptualisation of the state can overcome the limits of the debate as it has been framed so far and provide a deeper insight into how social relations shaped and were shaped by the development of early medieval polities. After reviewing the most significant historiographical contributions to the debate, the paper introduces the Strategic-Relational Approach to the state, as formulated by B. Jessop, as one that can provide a more nuanced understanding of early medieval polities. Particular emphasis is made on the analysis of class relationships and the articulation of hegemonic projects as two particularly fruitful lines of inquiry. Finally, the paper focuses on one particular instance of early medieval political practice, the politics of the land, as a means to illustrate the potential of the approach.     

QUALITY DIFFERENCES,THIRD‐DEGREE PRICE DISCRIMINATION,AND WELFARE

We propose a model with two markets to analyze the welfare implications of price discrimination with quality differences. In each market a local firm that operates in that market only competes against a global firm that operates in both markets. Local firms produce higher‐quality goods than the global firm. If the quality levels of the local firms' products are the same, price discrimination is never welfare‐decreasing. If they differ, discrimination is welfare‐increasing if quantity increases. Because of a positive allocation effect of price discrimination, there are parameter values such that welfare increases while total output decreases with price discrimination. (JEL D43, D60)     

Households,Families and Prospective Economic Mobility in Mexico

The study analyzed poverty as a function of households’ demographic composition using a longitudinal random sample of 4268 urban and rural households that were followed-up from 2005/6 to 2009/12 in Mexico to estimate short-term changes in living conditions. Well-being was measured as the dwelling unit’s number of rooms, water source, sanitary services, garbage disposal, and fuel. Mobility paths included not poor–not poor, poor–poor, not poor–poor, and poor–not poor. Independent variables included household composition, family characteristics, residential changes, schooling, and occupation. Female headship and older adults negatively impacted poverty, whereas economic dependents may be negatively or positively associated. Fertility incentives for low-income populations are not advisable. Working-age adults contribute only if income-generating opportunities exist locally.     

Assessing Participation and Effectiveness of the Peer-Led Approach in Youth Sexual Health Education: Systematic Review and Meta-Analysis in More Developed Countries

Sexual health education for young people is crucial not only for development of norms but also for protection against vulnerabilities during this stage in life. Although several systematic reviews have examined the effectiveness of peer-led sex education, none have focused on the extent of peer participation. The purpose of this review was to evaluate peer-led sexual health education interventions in more developed countries (MDCs). Electronic and manual searches across five social science, education, and medical databases were conducted. Fifteen articles were selected in total. Most (10 of 15) studies gave low or no responsibility to peers. The majority of articles found improvements in sexual health knowledge (13 of 14) and attitudes (11 of 15) at postintervention stages. Two studies showed improved self-efficacy, and three showed behavioral changes. A preliminary synthesis of effectiveness and level of participation was done. Meta-analysis revealed a large effect on knowledge change (Hedges’ g = 0.84, 95% confidence interval [CI]: 0.43 to 1.25) and a medium effect on attitude change (Hedges’ g = 0.49, 95% CI: 0.19 to 0.80). Peer-led interventions could be a powerful tool. This review shows that this approach is effective in changing knowledge and attitudes but not behaviors. Further research and action are needed to understand optimal implementation.     

The role of woodpeckers (family: Picidae) as ecosystem engineers in urban parks: a case study in the city of Madrid (Spain)

Urban Ecosystems - Many species of the family Picidae, such as the woodpeckers, excavate the tree-cavities where they nest. Frequently the cavities are used during a single breeding season and...