Consistent estimation in the bilinear multivariate errors-in-variables model

A bilinear multivariate errors-in-variables model is considered. It corresponds to an overdetermined set of linear equations AXB=C, A∈ℝ^m×n, B∈ℝ^p×q, in which the data A, B, C are perturbed by errors. The total least squares estimator is inconsistent in this case.  An adjusted least squares estimator is constructed, which converges to the true value X, as m →∞, q →∞. A small sample modification of the estimator is presented, which is more stable for small m and q and is asymptotically equivalent to the adjusted least squares estimator. The theoretical results are confirmed by a simulation study. Acknowledgements. We thank two anonymous reviewers for their suggestions and corrections.? A. Kukush is supported by a postdoctoral research fellowship of the Belgian office for Scientific, Technical and Cultural Affairs, promoting Scientific and Technical Collaboration with Central and Eastern Europe.? S. Van Huffel is a full professor with the Katholieke Universiteit Leuven.? I. Markovsky is a research assistant with the Katholieke Universiteit Leuven.? This paper presents research results of the Belgian Programme on Interuniversity Poles of Attraction (IUAP V-22), initiated by the Belgian State, Prime Minister's Office – Federal Office for Scientific, Technical and Cultural Affairs of the Concerted Research Action (GOA) projects of the Flemish Government MEFISTO-666 (Mathematical Engineering for Information and Communication Systems Technology), of the IDO/99/03 project (K.U. Leuven) “Predictive computer models for medical classification problems using patient data and expert knowledge”, of the FWO projects G.0078.01, G.0200.00, and G0.0270.02.? The scientific responsibility is assumed by its authors.     

Estimating the effectiveness of extension information systems using farm trials and subjective probabilities

A method of combining survey data and Dairy Herd Improvement Association (DHIA) records to achieve low cost farm trials is presented. Farm trials and surveys of current practices and production responses are useful to identify yield gaps between expectations predicted from experimental findings and actual field results. Different management schemes can be ranked using subjective probabilities and stochastic dominance to enhance successful implementation of research findings and to increase the feedback between researchers, extension workers, and producers. A survey of current masitis control practices and expected milk yield response is the example. Combining survey results with DHIA records allowed estimating the relationship between somatic cell counts (SCC) and milk yield. Eliciting beliefs about the relationship between SCC and milk yield showed that producers agreed with predictions from the statistical model. Subjective probabilities about SCC and mastitis control practices showed that our sample of experts and producers consistently ranked the different practices but extension agents had no consensus about the the most or least effective ones.     

Economic Comparison of Alternative Tillage Systems under Risk.

Stochastic dominance efficiency criteria are used to rank the net farm return distributions for four different tillage systems under six different farm scenarios. Pairwise comparisons of tillage systems are carried over incremental upper and lower risk-aversion coefficient (RAC) bounds identified for each farm scenario, based on the size and spread of the outcome distributions to identify regions where dominance may switch between tillage systems. Ridge-till systems are generally the dominant tillage system for all farm scenarios considered. No-till systems on clay loam soils are more dominant in the risk-preferring range and less dominant in the risk-averse range, which relates to the relatively larger range of net return values and smaller mean net return values generated by this tillage system. Conversely, the moldboard plow and chisel plow systems are more dominant in risk-aversion intervals and less dominant in the risk-preferring intervals for clay loam soils. In sandy soil scenarios, the ridge-till and no-till systems are dominant over the two fall tillage systems for all farm sizes, indicating that these tillage systems are more competitive with conventional tillage systems in lighter soil type situations. A sensitivity analysis between moldboard plow and no-till systems indicates that no-till would dominate in risk-preferring intervals, and an increase in no-till net farm returns of 16 per acre would change dominance in favor of no-till in risk-averse interval space. On a utilisé les critères d'efficacitéà dominance stochastique pour classer les divers niveaux de recettes agricoles nettes dans quatre systèmes différents de travail du sol, selon six scénarios d'exploitation. Des comparaisons en paires des systèmes de travail ont été faites en regard de tranches croissantes des limites supérieures et inférieures du coefficient d'aversion du risque (CER), établies pour chaque scénario d'après l'importance et l'étendue des distributions du rendement, dans le but d'identifier les régions où la dominance serait susceptible de passer d'un système de travail à l'autre. Le système de travail sur billons était en général le système dominant dans tous les scénarios d'exploitation examinés. La culture sans travail du sol sur loam argileux était plus dominante dans les intervalles d'acceptation du resque et moins dominante dans les intervalles d'aversion du resque, cequi s'explique au fait que ce système de travail donne lieu à une fourchette relativement plus large, mais aussi à une moyenne plus faible du revenu net. À l'inverse, le labour à la charrue classique et au chisel dominait davantage dans les intervalles d'aversion du risque. Dans les sols sableux, le travail sur billons et la culture sans labour l'emportaient sur les deux autres régimes dans toutes les tailles d'exploitation, ce qui porte à croire que, dans les sols plus légers, ces régimes sont plus concurrentiels avec les systèmes classiques. L'analyse de sensibilité entre le labour à la charrue et les systèmes sans travail du sol montre que ces derniers dominent dans les intervalles d'acceptation du risque et qu'un accroissement du revenu agricole net de 16 /acre ferait glisser la dominance vers les intervalles d'aversion du risque.     

Sterilization of short-term capital inflows—through lower interest rates?

Reductions in international interest rates are a major cause of capital flows to emerging economies. Increases in domestic interest rates are a frequent policy response to the resulting price increases. This is often unsuccessful. The paper suggests a theoretical explanation based on distinctive features of emerging financial markets, including imperfect asset substitutability and imperfect capital mobility for some sectors of the economy. It concludes that the appropriate policy response to capital inflows may be lower interest rates.     

There's something about saving …

The paper considers how people should plan their saving, given certain assumptions about inheritance and changes in household circumstances. The results are produced by a model that takes into account tax and state benefits as well as various private savings vehicles. It concludes that, for many households, saving for retirement through a ‘pension’ might not be optimum and that the best strategy is to vary the incidence and allocation of saving in response to changes in household circumstances.     

More thinking on research methods for the resource‐based perspective

We re‐examine the benefits of using a broader set of research methods to address key questions associated with the resource‐based view (RBV) of the firm. In responding to Levitas and Chi, we consider how research inside organizations can complement and augment research relying on secondary data. Copyright © 2002 John Wiley & Sons, Ltd.     

Satisfaction drivers for Internet service technology among stock brokerage customers in Thailand

Many financial services firms are offering the Internet as a self-service technology (SST), for online stock trading, in an effort to increase effciency and give customers greater access. It is important to understand how this technology will influence customer satisfaction. This paper reports results of exploratory research to identify sources of customer satisfaction and dissatisfaction with the service encounter in Thai stockbrokerage firms. Results show that customers and service providers determine sources of customer dis/satisfaction differently, depending on whether the service encounter is technology-based or interpersonal. Different customer profiles give rise to segmentation in response to the use of Internet technology in this industry.