Networks of queues with infinite servers in each node applied to the management of a two echelons repair system

After a report of results about infinite servers queues, essentially on its busy period, a model is built, using networks of queues with infinite servers in each node, to study a two echelons repair system for example of a fleet of aircraft, shipping or trucks. The customers are the failures, and their service time is the time that goes from the instant at which they occur till they are completely repaired. The failing repairs occur in a base or in a remote station. The whole failures detected in the base are repaired there. Some of the failures detected in the station are repaired there and the others in the base. The results referred above allow the determination of a two echelons repair system performance measures. In this application, models of Carrillo （1991） and Ferreira （1996） are considered, improved and completed. The theory is illustrated with a numerical example.     

The mediating role of leader–member exchange: a study of job satisfaction and turnover intentions in temporary work

This paper focuses on turnover intentions in temporary work. Specifically, we analyse whether job satisfaction and leader–member exchange (LMX) play the same role as antecedents of turnover intentions for both temporary and permanent employees. Results from a total‐effects moderation model based on a survey of 593 individuals placed by a temporary work agency suggest that temporary work lessens the impact that high job satisfaction has in terms of reducing turnover intentions. Furthermore, while for permanent employees, high‐quality LMX relationships play a central role in the link between job satisfaction and turnover intentions; for temporary employees, job satisfaction is less important in the formation of high‐quality LMX relationships. Therefore, we contribute to knowledge on turnover intentions in temporary work by showing that within this context, turnover intentions cannot be directly remedied by high job satisfaction and that temporary work inhibits LMX's reinforcing role in the relationship between job satisfaction and turnover intentions.     

Mobile Dwelling Unit Developed by a Group of Mechanical Engineering Design Students

The increasing number of homeless people is one of the most burning problems of nowadays world. Society has to find the way to fight against it and provide help to those people that have no place to stay. For short-term interventions, the application of the mobile dwelling units seems to be the only possible solution. However, existing mobile dwelling units are rather limited to specific areas of application. A group of students faced this problem and decided to develop an alternative, more universal mobile dwelling unit that will fulfil a wide range of different technical and social requirements at a reasonable price. The paper describes a systematic approach to development of the mobile dwelling unit, which was performed as a part of the education process at the Faculty of Mechanical Engineering, University of Maribor. The project presented is interdisciplinary. In addition to the educational aspect that is emphasized in this paper, technical, economic and social aspects of the project have also a very important role. From educational point of view, the project was concluded successfully. Moreover, we believe our proposal for a mobile dwelling unit is both novel and suitable for general application. This revised version was published online in July 2006 with corrections to the Cover Date.     

GMM estimation of a structural demand model for yogurt and the effects of the introduction of new brands

The demand structure for yogurt is assumed to be properly described by a one level nested logit model that is applied to aggregate market data. Given the presence of endogenous regressors, suitably lagged endogenous variables (Arellano and Bover in J Econom 68:29–51, 1995; Blundell and Bond in J Econom 87:115–143, 1998) are proposed as instrumental variables. The validity of this set of instruments is discussed and price elasticities and marginal costs are recovered from the demand estimates. Total welfare gains associated to the introduction of two new brands by the same manufacturer are finally computed. Prices and profits decreased and total welfare increased.     

Investing in a relationship

A principal can make an investment anticipating a repeated relationship with an agent, but the agent may appropriate the returns through ex post bargaining. I study how this holdup problem and efficiency depend on the contracting environment. When investment returns are observable, informal contracts ex post can be more efficient than formal contracts, as they induce higher investment ex ante: the principal invests not only to generate direct returns, but also to improve relational incentives. Unobservability of returns increases the principal's ability to appropriate the returns but reduces her ability to improve incentives. The optimal information structure depends on bargaining power.     

The conservation against development paradigm in protected areas: Valuation of ecosystem services in the Doñana social-ecological system (southwestern Spain)

The ecosystems of the Doñana social-ecological system (southwestern Spain) provide numerous ecosystem services to society. We valued the most important ecosystem services through a market-based approach, revealed-preference and stated-preference methods to assess the conservation effectiveness of the Doñana Protected Area, with consideration of existing human activities in surrounding lands. We also analysed the spatial distribution of the ecosystem services beneficiaries and the scale of their related markets. We found a clear trade-off between the local and global market values of ecosystem services because landscape management outside of the Doñana Protected Area promotes the provision of ecosystem services associated with international markets. Our results suggest that a conservation against development model occurs in the Doñana social-ecological system, in which land use intensification takes place outside of the Protected Area borders as a result of promoting marketed ecosystem services, while biodiversity conservation is the main activity inside the Protected Area. We conclude that protected areas should be part of a larger-scale, adaptive landscape management strategy in which conservation planning should be the focal element in coordinating sectoral policies in the context of social-ecological systems.     

Survival of Japanese subsidiaries in the Middle East and North Africa

This paper considers factors affecting survival of foreign subsidiaries in the context of Japanese foreign equity ventures in the Middle East and North Africa (MENA). Three new institutional variables, economic distance, economic freedom distance and subsidiary density, are examined as determinants of survival while controlling for other determinants previously established in the literature. The findings support our hypotheses. We found that economic distance and economic freedom distance exhibit significant positive and negative relationships respectively with the survival of Japanese FDI in the MENA region, and moderate positive relationship between subsidiary density and subsidiary survival.     

Obesity and happiness

This article provides insight on the relationship between individual obesity and happiness levels. Using the latest available panel data from Germany German Socio-Economic Panel (GSOEP), UK British Household Panel Survey (BHPS), and Australia Household, Income and Labour Dynamics in Australia (HILDA), we examine whether there is statistical evidence on the impact of overweight on subjective well-being. Instrumental Variable (IV) analysis is utilized under the presence of endogeneity, stemming from several explanatory variables. Results indicate that in all three countries obesity has a negative effect on the subjective well-being of individuals. The results also have important implications for the effect of other socio-demographic, economic and individual characteristics on well-being.     

Diversification strategies and scope economies: evidence from a sample of Italian regional bus transport providers

A growing number of Local Public Transport (LPT) companies diversify their production lines by providing a large set of services. We investigate the cost structure of a sample of LPT companies operating in Italy and assess the presence and the magnitude of scope economies. We split the whole sample of firms according to their diversification strategy: private firms, mainly diversifying in competitive transport related services and public firms providing nontransport services in regulated markets. Scope economies appear sizeable for both groups but higher for firms pursuing a transport related strategy, suggesting caution in the multiutility development pursued by public LPT firms in Italy.