Systematic Effects of Capital Service Price Definition on Perceptions of Input Substitution

Earlier attempts at reconciling disparate substitution elasticity estimates examined differences in separability hypotheses, data bases, and estimation techniques, as well as methods employed to construct capital service prices. Although these studies showed that differences in elasticity estimates between two or three studies may be attributable to the aforementioned features of the econometric models, they have been unable to demonstrate this link statistically and establish the existence of systematic relationships between features of the econometric models and the perception of production technologies generated by those models. Using sectoral data covering the entire production side of the U.S. economy, we estimate 34 production models for alternative definitions of the capital service price. We employ substitution elasticities calculated from these models as dependent variables in the statistical search for systematic relationships between features of the econometric models and perceptions of the sectoral technology as characterized by the elasticities. Statistically significant systematic effects are found between the monotonicity and concavity properties of the cost functions and service price–technical change specifications as well as between substitution elasticities.     

A new class of measurement-error models,with applications to dietary data

Measurement-error modelling occurs when one cannot observe a covariate, but instead has possibly replicated surrogate versions of this covariate measured with error. The vast majority of the literature in measurement-error modelling assumes (typically with good reason) that given the value of the true but unobserved (latent) covariate, the replicated surrogates are unbiased for latent covariate and conditionally independent. In the area of nutritional epidemiology, there is some evidence from biomarker studies that this simple conditional independence model may break down due to two causes: (a) systematic biases depending on a person's body mass index, and (b) an additional random component of bias, so that the error structure is the same as a one-way random-effects model. We investigate this problem in the context of (1) estimating distribution of usual nutrient intake, (2) estimating the correlation between a nutrient instrument and usual nutrient intake, and (3) estimating the true relative risk from an estimated relative risk using the error-prone covariate. While systematic bias due to body mass index appears to have little effect, the additional random effect in the variance structure is shown to have a potentially important effect on overall results, both on corrections for relative risk estimates and in estimating the distribution of usual nutrient intake. However, the effect of dietary measurement error on both factors is shown via examples to depend strongly on the data set being used. Indeed, one of our data sets suggests that dietary measurement error may be masking a strong risk of fat on breast cancer, while for a second data set this masking is not so clear. Until further understanding of dietary measurement is available, measurement-error corrections must be done on a study-specific basis, sensitivity analyses should be conducted, and even then results of nutritional epidemiology studies relating diet to disease risk should be interpreted cautiously.     

The Structure of Mental Health: Higher-Order Confirmatory Factor Analyses of Psychological Distress and Well-Being Measures

Social Indicators Research - This paper addresses the question of whether psychological distress and subjective well-being are the opposite poles of the same axis of mental health or independent...     

A biweight approach to estimate currency exchange rate: the Nigerian example

In this article, we propose a biweight approach to a real-life location problem, namely, the estimation of a realistic exchange rate for the Nigerian currency, naira (for easy reference, we denote the exchange rate parameter byθ).

Our proposal is essentially a critic of the methods being used by the Central Bank of Nigeria (CBN) to derive its estimate θ_CBN of θ. The CBN generates the necessary data by periodically organizing a foreign exchange market (FEM) where it sells a certain amount of US dollars to authorized foreign exchange dealers. (The amount of dollars available for sale is usually inadequate to meet aggregate demand, so there is literally a 'scramble' among dealers for a 'slice of the cake'.) During each session of FEM, each dealer quotes: (a) how much naira (variable Y) it will pay for US$1, and (b) the amount of US dollars (variable X) it wants to buy. The CBN estimates, based on observations of Y, have been found to be unstable and part of the problem seems to lie with the fact that a few atypical or outlier values are generated at FEM sessions and CBN estimation methods are not resistant to these extreme values.

This article presents a robust/resistant model which is designed to tackle the problem of outliers head on: we exploit the resistance property of the biweight to help reduce the influence of any outlier on the final biweight estimate θ_bw. Furthermore, we use the biweight weight, in conjunction with X, as an instrument to check against generation of outliers at FEM.     

Family-Responsive Variables and Retention-Relevant Outcomes Among Employed Parents

This study examined the influence offamily-responsive variables and the moderating influence of gender on the retention-relevant outcomes of organizational commitment and turnover intentions. Data were obtained with the aid of structured questionnaires from employed parents (N = 228) in a human service authority in Hong Kong. Results of regression analysis revealed that satisfaction with work schedule flexibility and supervisor work family support were related to both retention-relevant outcomes. Contrary to our prediction, gender did not moderate the influence of any of the family-responsive variables on the retention-relevant outcomes. Limitations of the study, directions for future research and implications of the findings for enhancing the effectiveness of family-responsive human resource policies are discussed.     

A Discussion of Findings and Their Possible Implications from a Workshop on Bioterrorism Threat Assessment and Risk Management

In November 2001, the Monterey Institute of International Studies convened a workshop on bioterrorism threat assessment and risk management. Risk assessment practitioners from various disciplines, but without specialized knowledge of terrorism, were brought together with security and intelligence threat analysts to stimulate an exchange that could be useful to both communities. This article, prepared by a subset of the participants, comments on the workshop's findings and their implications and makes three recommendations, two short term (use of threat assessment methodologies and vulnerability analysis) and one long term (application of quantitative risk assessment and modeling), regarding the practical application of risk assessment methods to bioterrorism issues.     

Complementary properties of binary relations

After defining the complementary relation R of a binary relation R on a set X, this paper constructs the binary relation C (is a complementary property of) on the set P of nine well known elementary properties that R might possess. It deduces some theorems about C; especially that symmetry is the only one of these possible properties of R on X that is possessed by C on P. The set P may be enlarged to contain other elementary properties of R on X without changing the truth of these theorems, when the symbols of sets are properly modified. Finally, the paper discusses the desirability of a general theory of elementary properties of binary relations for the further development of statistical decision theory.