Estimators for the common principal components model based on reweighting: influence functions and Monte Carlo study

The common principal components model for several groups of multivariate observations is a useful parsimonious model for the scatter structure which assumes equal principal axes but different variances along those axes for each group. Due to the lack of resistance of the classical maximum likelihood estimators for the parameters of this model, several robust estimators have been proposed in the literature: plug-in estimators and projection-pursuit (PP) type estimators. In this paper, we show that it is possible to improve the low efficiency of the projection-pursuit estimators by applying a reweighting step. More precisely, we consider plug-in estimators obtained by plugging a reweighted estimator of the scatter matrices into the maximum likelihood equations defining the principal axes. The weights considered penalize observations with large values of the influence measures defined by Boente et al. (2002). The new estimators are studied in terms of theoretical properties (influence functions and asymptotic variances) and are compared with other existing estimators in a simulation study.     

Workers or Employers: Who is Shaping Wage Inequality?

An extensive micro data set matching firms, establishments and their employees, is used to study the determinants of earnings inequality in Portugal and its evolution from 1983 to 1992, with the Theil index, its decomposition, and the decomposition of its change as tools of analysis. The relevance of both worker and employer attributes in shaping earnings inequality and its trend is quantified. The impact of the firm on wage inequality in a European country is compared to the situation in the USA, and the results suggest that a more regulated and centralized European bargaining system might reduce the scope for firm action. A profile of an economy undergoing modernization, where rising labour market inequality signalled the lack of an adequate labour force, can be drawn, with the minimum wage having nonetheless a certain narrowing effect on the earnings distribution.     

A multiple dispatch and partial backup hypercube queuing model to analyze emergency medical systems on highways

The hypercube is a spatially distributed queuing model based on Markovian analysis approximations, used to analyze the configuration and operation of server-to-customer emergency systems. In the present study we adapted the model to analyze emergency medical systems (EMS) on highways, which operate within particular dispatching policies. The study takes into consideration that: the emergency calls are of different types; the servers are distinct (e.g., rescue ambulances, medical vehicles); only certain servers in the system can service calls in a given region (partial backup); and, depending on the type of call, one or more identical or distinct servers are immediately dispatched to service such calls (multiple dispatch). We also consider that the arriving calls take place either along the highway or at the home location of a server – in which case the server does not need to travel to the call location. Finally, we analyzed the computational results of applying such an approach to the case study of an EMS operating on Brazilian highways.     

When should a firm expand its business? : The signaling implications of business expansion

We examine an incumbent's trade-off between the improved efficiency that business expansion facilitates and the signaling role that business expansion plays in conveying information to potential entrants about the state of demand. We demonstrate that both separating and pooling equilibria survive the Intuitive Criterion. Essentially, in contrast to models with asymmetric information about unit cost, incumbents' benefits from investing in a signal are not necessarily monotonic in the state of demand. We investigate how the extent of informativeness of the outcome depends on the enhanced efficiency that the incumbent's expansion facilitates and the priors of the entrant.     

Licensing information goods

A significant amount of research on patent licensing and the diffusion of knowledge is organized around static frameworks of analysis. Patent holders, however, may face a dynamic problem, namely the intertemporal consistency problem of the durable-goods monopolist that is induced by durability on the demand side. Licensing practices such as exclusive licensing contracts and most favored customer clauses allow patentees to solve or mitigate this dynamic consistency problem. There are situations, however, where these practices are not possible either due to the nature of the patent (the case of information goods) or due to compulsory patenting laws. We study the effects of the intertemporal consistency problem on patent licensing in these situations. Relative to the existing literature, we obtain the following main results: (i) all of the firms that remain in the industry will be using the innovation; (ii) royalty licensing may be superior to fixed-fee or auction licensing from the licensor's point of view; (iii) social welfare and consumer surplus may be lower than when the patent holder can commit not to make additional sales; (iv) even for non-drastic innovations, the price of the good that is produced may be lower than the competitive price corresponding to the initial situation (before the innovation was discovered).     

Assessing the regional digital divide across the European Union-27

Despite the efforts devoted to the analysis of the digital divide over the last years, the regional evidence on this issue is still scarce. Within this context, the goals of this paper are twofold: (1) measuring the digital divide across the regions of the 27 Member States and within each country and (2) explaining the observed regional disparities. The analysis leads to identify Dutch regions as the Top-10 in ICT, while Greece and Bulgaria occupy the Bottom-10. Therefore, results show that the regional digital divide reflects to some extent the income gap. However, regional policy seems to be having some positive implications for technology adoption. In particular, the rural-versus-urban dimension of the digital gap appears to be less important than it is usually claimed to. Likewise, some evidence is found of the role of cultural and institutional factors in ICT adoption, an issue that has not been previously analyzed at the regional level.     

Network embeddedness,headquarters entrepreneurial orientation,and MNE international performance

The aim of this paper is to examine the role played by external and internal network embeddedness in the headquarters entrepreneurial orientation of multinational enterprises (MNEs), and the role of the latter in MNE performance. Drawing on responses from CEOs in a sample of 143 European MNEs, our study offers evidence for the antecedent role of network embeddedness on headquarters entrepreneurial orientation on the one hand, and for the positive impact of headquarters entrepreneurial orientation on international performance on the other. Our findings contribute to the network view of MNEs in the international business and international entrepreneurship literature by disentangling the complex phenomenon of entrepreneurship in MNEs, partly explained by its multiple embeddedness in external and internal networks, and by studying its impact on international performance.     

Marketing aspects of environmental practices of multinational enterprises in host countries: A Brazilian case study

This article investigates both the marketing and the production activities of a multinational enterprise (MNE) operating in the Brazilian chemical industry. The case chosen illustrates how the MNE has managed to adapt or to upgrade some of its main policies, programs, production activities, and products in conformity with both its long-term strategic positioning and the host country's environmental regulatory policy. The company established two effective environmental programs that deserve mention. One of the programs has been set up to generate receipts through the provision of environmental services for a price. The other one pursued systematic procedures to better serve clients through customized applications of waste reduction practices. The latter reveals how proactive companies may profit from effectively envisaging the whole product cycle along their value chain. © 1995 John Wiley & Sons, Inc.     

Is the hotel classification system a good indicator of hotel quality?: An application in Spain

This paper analyses whether the hotel classification system is a good indicator of hotel quality, where quality is defined to be satisfying the expectations and needs of the client. We conducted our research in Spain, where a five-category system using stars is employed. To be exact, the hotel sector of one autonomous community (Cantabria, located in northern Spain) was studied, given that it is these autonomous regions that have exclusive authority to regulate and promote tourism. The results of the study confirm that even though significant quality differences are seen between the different categories, the ranking by quality does not correspond to that by categories. This supports the idea that quality is associated with the delivery of a service according to client expectations, more than it is with establishment category.     

Risky behaviours of males and females in a Spanish suburban community

Health is determined by an accumulative process, so a perspective on life cycle is crucial in any health prevention programme. As a consequence of this accumulative dimension, lifestyles are a key determinant of the state of health of older people. The main contribution of this paper is to explain gender differences in lifestyle and the implications of lifestyle in men's and women's states of health. We have implemented our empirical analysis into Spanish society through the use of a self‐elaborated survey. From this survey, we have drawn a subsample of 938 people older than 14 years old who live in the Spanish neighbourhood of Casablanca, Zaragoza (452 men and 486 women). We conclude that men tend to consume more substances that may negatively affect their state of health (alcoholic beverages, tobacco products and coffee), and they are also less careful in keeping an adequate weight and dental hygiene. On the other hand, women tend to be more sedentary. These results are decisive for policy makers that strive to improve the citizens’ state of health, because it is not only important to improve the quality and extension of healthy goods and services, but also to promote healthy lifestyles.