An approximation method to derive confidence intervals for quantiles with some applications

Standard jackknife confidence intervals for a quantile Q _y (β) are usually preferred to confidence intervals based on analytical variance estimators due to their operational simplicity. However, the standard jackknife confidence intervals can give undesirable coverage probabilities for small samples sizes and large or small values of β. In this paper confidence intervals for a population quantile based on several existing estimators of a quantile are derived. These intervals are based on an approximation for the cumulative distribution function of a studentized quantile estimator. Confidence intervals are empirically evaluated by using real data and some applications are illustrated. Results derived from simulation studies show that proposed confidence intervals are narrower than confidence intervals based on the standard jackknife technique, which assumes normal approximation. Proposed confidence intervals also achieve coverage probabilities above to their nominal level. This study indicates that the proposed method can be an alternative to the asymptotic confidence intervals, which can be unknown in practice, and the standard jackknife confidence intervals, which can have poor coverage probabilities and give wider intervals.     

On the advantages of economically designed variable sample sizes and sampling intervals T2 control chart: double warning lines scheme

Faraz and Parsian (Stat Pap 47:569–593, 2006) have shown that the double warning lines (DWL) scheme detects process shifts more quickly than the other variable ratio sampling schemes such as variable sample sizes (VSS), variable sampling intervals (VSI) and variable sample sizes and sampling intervals (VSSVSI). In this paper, the DWL T² control chart for monitoring the process mean vector is economically designed. The cost model proposed by Costa and Rahim (J Appl Stat 28:875–885, 2001) is used here and is minimized through a genetic algorithm (GA) approach. Then the effects of the model parameters on the chart parameters and resulting operating loss is studied and finally a comparison between all possible variable ratio sampling (VRS) schemes are made to choose the best option economically.     

Temporary jobs and job search effort in Europe

Using longitudinal data on individuals from the European Community Household Panel (ECHP) for eleven countries during 1995-2001, I investigate temporary job contract duration and job search effort. The countries are Austria, Belgium, Denmark, Finland, France, Greece, Ireland, Italy, the Netherlands, Portugal and Spain. I construct a search model for workers in temporary jobs which predicts that shorter duration raises search intensity. Calibration of the model to the ECHP data implies that at least 75% of the increase in search intensity over the life of a 2+ year temporary contract occurs in the last six months of the contract. I then estimate regression models for search effort that control for human capital, pay, local unemployment, and individual and time fixed effects. I find that workers on temporary jobs indeed search harder than those on permanent jobs. Moreover, search intensity increases as temporary job duration falls, and roughly 84% of this increase occurs on average in the shortest duration jobs. These results are robust to disaggregation by gender and by country. These empirical results are noteworthy, since it is not necessary to assume myopia or hyperbolic discounting in order to explain them, although the data clearly also do not rule out such explanations.     

Innovation, progress, entrepreneurship and cultural aspects

In the case of economic progress, some of the literature has considered economic growth and economic progress to be the same thing. However, there is a relevant difference between the two concepts. As Holcombe states, economic growth considers the quantity of products and economic progress the quality of products. Innovation has been considered as a key factor to promote economic progress. A culture would have a direct and an indirect effect on innovation through entrepreneurship. The goal of this paper is to analyze the relationship between culture and innovation. To carry out this study, an empirical estimation has been developed for the case of 11 countries.     

Social capital as a distinctive feature of Social Economy firms

In recent years, the growing importance in developed countries of the Social Economy sector and the contribution of social capital to regional economic development are being studied in depth. Linking these two fields of research, the aim of the present work is to analyse the social capital endowments of Social Economy firms in comparison to those in traditional profit-maximizing firms. To do so, a literature review will be firstly carried out to clarify both the concept of social capital and, more specifically, its relation with entrepreneurship and social enterprises. In the empirical section, the social capital endowments both of social firms (cooperatives and owned-worker enterprises) and traditional firms are compared using data from two surveys conducted in Andalusia, a lagged Spanish region with long tradition in the Social Economy sector. Results show that social capital endowments measured through cooperation agreements and company links with local suppliers and costumers are higher in cooperatives and worker-owned companies. Therefore, Andalusian authorities must continue with its support policy to these enterprises as a mean to reinforce the regional economic development.     

Design parameters of the strategic planning process and organizational performance—a quantitative analysis of empirical research

After 50 years of research in strategic management, the design of strategic planning processes is still on the agenda for scholarly research. Using a quantitative meta-analysis, we examine empirical studies on the relationship between organizational performance and the design parameters of the strategic planning process that can be controlled by a firm. Whereas existing literature reviews focus on the effect of strategic planning on performance, this meta-analysis also considers the role of the location and participants in the strategic planning process, the distinct properties of strategic planners and the intensity of the planning method used. The effect sizes of existing primary studies are harmonized for better comparison and aggregated for a total effect. The total effect is tested for significance and checked for homogeneity.     

Structural equation modeling with ordinal variables: a large sample case study

In the behavioral sciences, response variables are often non-continuous, ordinal variables. Conventional structural equation models (SEMs) have been generalized to accommodate ordinal responses. In this study, three different estimation methods on real data were performed with ordinal variables. Empirical results obtained from the different estimation methods on given real large sample educational data were investigated and compared to recent simulation results. As a result, even very large sample is available, model estimations and fits for ordinal data are affected from inconvenient estimation methods thus it is concluded that asymptotically distribution free estimation method specialized for ordinal variables is more convenient way to model ordinal variables.     

The impact of external forces on cartel network dynamics: Direct research in the diamond industry

This paper describes the impact of external environmental forces on cartel networks. Using a case research approach, this report examines two leading business networks within one industry, over time. The results suggest that (a) bargaining power of intermediaries increases with the advent of new and powerful actors, (b) process activities that cartels previously controlled are being outsourced to new actors sometimes based in developing countries, (c) other actors are acquiring resources once dominated by a cartel, (d) external forces triggered by the illegal diamond trade, such as international regulatory constraints, no longer favour cartels like De Beers, and (e) over time, these and additional environment factors are forcing actors like De Beers who perform rigid process activities to become more flexible. For example, forces are moving cartels which relied previously on hand-picked intermediaries in highly controlled networks to market their products to adopt a flexible market-focused expansion of operations in retail contexts.     

A buyer's perspective on collaborative versus transactional relationships

This research examines collaborative and transactional relationships in buying firms to determine whether collaborative relationships offer greater benefits than transactional relationships, and to ascertain which relational factors drive satisfaction and performance for both collaborative and transactional relationship types. Factor analysis, t-tests and step-wise regression were used to analyze data from a survey of buying firms. Results show that collaborative relationships offer higher levels of satisfaction and performance than transactional relationships. Satisfaction factored into two separate constructs: satisfaction with the relationship and satisfaction with the results. Of the relational factors examined, trust is the most important predictor of performance and satisfaction with the relationship regardless of the type of relationship examined.     

Supplier traits for better customer firm innovation performance

Previous research on embedded ties with suppliers in an innovation context has ignored the need for customer firms to assess and select suppliers on the basis of market orientation strategies and relationship marketing attributes. To address this void, this study investigates the effects of suppliers' downstream customer orientation and supplier-customer homophily (i.e., similarity of the supplier and the customer) on the customers' innovation performance. Data pertaining to new product development projects with contributions from supplier firms was collected on both sides of the supplier-customer dyad. The analysis shows that downstream customer orientation and supplier-customer homophily have a significant impact on the customer firms' new product efficiency (i.e., project cost and project speed) and new product effectiveness (i.e., innovativeness), which in turn positively influence new product performance in terms of profitability, market share, and growth.