Impact of competitive conditions on supplier evaluation: a construction supply chain case study

This research proposes a multi-criteria decision-making (MCDM) framework and demonstrates the impact of competitive conditions on supplier evaluation process for construction supply chains. The paper focuses on the supply chain of a large-scale housing project in order to illustrate the role of competitive capability and suppliers’ profile and its influence on supplier evaluation based on prevailing supply/market conditions. Various scenarios are investigated to demonstrate the impact of competition on supplier evaluation. The contribution of the study lies in highlighting the impact of supply/market conditions on MCDM decisions causing supplier evaluation ‘imbalance’ and MCDM usage. It is expected that the study will be useful for project management, construction, supply chain management, sourcing professionals. The findings of the study are generalisable to projects-based situations such as petroleum refinery and ship building where bill of materials typically consists of thousands of items and a large number of suppliers are involved.     

Improvements in Life Expectancy: 1960–1995 an Exploratory Analysis

Human history observed significant changes in life expectancy over the last three and half decades (1960–1995). This study attempts to explore the determinant factors behind improvements in life expectancy in most of the countries in the Post World War II period. In this context the study estimates a double logarithmic convergence type model where the dependent variable is relative change of life over the period and the explanatory variables are initial per capita real gross domestic product, initial per capita calorie intake as percentage of requirement, adult literacy rate at the initial point of time, and initial physician per thousand of population. The study estimates different variants of the basic model. Female population has been treated separately. All estimates have been offered for three broad income groups low, middle and high. An attempt is also made to take into account the effects of some public health measures such as access to safe drinking water and access to sanitation.     

Semiparametric estimation for the dispersion parameter in the analysis of over- or underdispersed count data

This paper investigates several semiparametric estimators of the dispersion parameter in the analysis of over- or underdispersed count data when there is no likelihood available. In the context of estimating the dispersion parameter, we consider the double-extended quasi-likelihood (DEQL), the pseudo-likelihood and the optimal quadratic estimating (OQE) equations method and compare them with the maximum likelihood method, the method of moments and the extended quasi-likelihood through simulation study. The simulation study shows that the estimator based on the DEQL has superior bias and efficiency property for moderate and large sample size, and for small sample size the estimator based on the OQE equations outperforms the other estimators. Three real-life data sets arising in biostatistical practices are analyzed, and the findings from these analyses are quite similar to what are found from the simulation study.     

A birth and death process with logistic mean population

An example of density dependent-birth and death process whose mean satisfies the logistic equation as proposed by Gompertz is given. Explicit expressions for the probability generating function and non-trivialstationarydistribution are obtained.     

The Effects of Modern Treaties and Opt-In Legislation on Household Incomes in Aboriginal Communities

This paper investigates the influence of country risks, including economic, financial, and political risks, on income inequality for a broad sample of 110 countries. Our empirical results reveal that higher economic and political risks generally lead to higher inequality. Lower income country appears to have higher income inequality. Furthermore, with the consideration of the non-monotonic effect of country risk, the improvement of income distribution is only sustainable dynamically after a certain threshold level of country risk has been brought down. Policymakers should improve the level of country stability by exploring the benefits of country risk reduction in order to improve income distribution.     

Bayesian variable selection using an adaptive powered correlation prior

The problem of selecting the correct subset of predictors within a linear model has received much attention in recent literature. Within the Bayesian framework, a popular choice of prior has been Zellner's g$g$-prior which is based on the inverse of empirical covariance matrix of the predictors. An extension of the Zellner's prior is proposed in this article which allow for a power parameter on the empirical covariance of the predictors. The power parameter helps control the degree to which correlated predictors are smoothed towards or away from one another. In addition, the empirical covariance of the predictors is used to obtain suitable priors over model space. In this manner, the power parameter also helps to determine whether models containing highly collinear predictors are preferred or avoided. The proposed power parameter can be chosen via an empirical Bayes method which leads to a data adaptive choice of prior. Simulation studies and a real data example are presented to show how the power parameter is well determined from the degree of cross-correlation within predictors. The proposed modification compares favorably to the standard use of Zellner's prior and an intrinsic prior in these examples.     

Index-number tests and the common-scaling social cost-of-living index

For a change in prices, the common-scaling social cost-of-living index is the equal scaling of each individual’s expenditure level needed to restore the level of social welfare to its pre-change value. This index does not, in general, satisfy two standard index-number tests. The reversal test requires the index value for the reverse change to be the reciprocal of the original index. And the circular test requires the product of index values for successive price changes to be equal to the index value for the whole change. We show that both tests are satisfied if and only if the Bergson–Samuelson indirect social-welfare function is homothetic in prices, a condition which does not require individual preferences to be homothetic. If individual preferences are homothetic, however, stronger conditions on the Bergson–Samuelson indirect must be satisfied. Given these results, we ask whether the restrictions are empirically reasonable and find, in the case that individual preferences are not homothetic, that they make little difference to estimates of the index.     

Some finite sample properties of generalized ridge regression estimators

In this paper we study the mean square error properties of the generalized ridge estimator. We obtain the exact and the approximate bias and the mean square error of the operational generalized ridge estimator in terms of G( ) functions. We show, among other things, that the operational generalized ridge estimator does not dominate the ordinary least squares estimator up to a certain order of approximation. Finally, we note that the iterative procedures to obtain coverging ridge estimators should be used with caution.