Issues in the estimation and application of latent structure models of choice

Our paper provides a brief review and summary of issues and advances in the use of latent structure and other finite mixture models in the analysis of choice data. Focus is directed to three primary areas: (1) estimation and computational issues, (2) specification and interpretation issues, and (3) future research issues. We comment on what latent structure models have promised, what has been, to date, delivered, and what we should look forward to in the future.     

Vulnerability and industrial hazards in industrializing countries: an integrative approach

The extra vulnerability of industrializing countries to environmental problems and industrial accidents cannot be understood or solved by a ‘normal’ scientific analysis. Aspects of the social and institutional context must be included, through analyses based on post-normal science. The standard two-dimensional classification of PNS is modified to have axes ‘social ‘and institutional vulnerabilities’ and ‘complexity of technological hazards’. The analysis is mainly applied to the case of the relatively rare accidents with catastrophic potential. In these, the deaths per accident in India, Mexico and Brazil are much greater than in the industrialized countries. This discrepancy arises partly from location of such plants near residential communities for marginalized workers and their families. Other socio-political factors are relevant, as the role of these countries in the global production system, the enforcement of safety and planning laws, quality of housing, and lifestyle of residents. Reducing the vulnerability of industrializing countries will therefore require major social policies and a comprehension of the limits of the normal scientific and economic approaches to such problems.     

How similar is the world in the internet era? A comparison of e‐business in China,Russia, and Sweden

Much has been written about how e‐business can serve as a strong homogenizing influence and essentially make the world into one market. Yet, little research has empirically investigated this question. This study seeks to describe e‐business activity in China, Sweden, and Russia to identify similarities and differences in the portfolios of e‐business applications in these countries. Our results indicate that different e‐business applications are emerging as more prevalent in different countries. © 2006 Wiley Periodicals, Inc.     

Numerical issues in threshold autoregressive modeling of time series

This paper analyses the contribution of various numerical approaches to making the estimation of threshold autoregressive time series more efficient. It relies on the computational advantages of QR factorizations and proposes Givens transformations to update these factors for sequential LS problems. By showing that the residual sum of squares is a continuous rational function over threshold intervals it develops a new fitting method based on rational interpolation and the standard necessary optimality condition. Taking as benchmark a simple grid search, the paper illustrates via Monte Carlo simulations the efficiency gains of the proposed tools.     

The Essential Features of Technology and Technology Education: A Conceptual Framework for the Development of OBE (Outcomes Based Education) Related Programmes in Technology Education

It appears that programme development in technology education is emerging from an atheoretical perspective. This could be attributed to the absence/neglect of conceptual frameworks (philosophical underpinning) in the development of programmes in technology education. This article explores the role of the content dimension of the 'essential features' of technology and technology education in OBE (Outcomes Based Education) related programme development. An instructional programme was developed using criteria derived from the essential features of technology and technology education. In order to gauge learners' experience, in relation to these essential features, a qualitative case study involving 20 learners was undertaken at a College of Education. Engagement with theprogramme proved to be an empowering experience for the learners who had hitherto not had the opportunity to experience a formal programme in technology education. Although it could not be proved conclusively that cognitive development had occurred, positive inter-dependence,shared responsibility, social skills and enhanced learning were evident. The study has shown that criteria derived from the 'essential features' of technology and technology education could serve as a reliable yardstick to measure the extent of learning in relation to these essential features     

A comparison of several approximations to the power function of the likelihood ratio test in covariance structure analysis*

In this paper we compare alternative asymptotic approximations to the power of the likelihood ratio test used in covariance structure analysis for testing the fit of a model. Alternative expressions for the noncentrality parameter (ncp) lead to different approximations to the power function. It appears that for alternative covariance matrices close to the null hypothesis, the alternative ncp's lead to similar values, while for alternative covariance matrices far from H_o the different expressions for the ncp can conflict substantively. Monte Carlo evidence shows that the ncp proposed in Satorra and Saris (1985) gives the most accurate power approximations.