There is growing interest in quantitatively analyzing in vivo image data, as this facilitates objective comparisons and measurement of effect. In this regard, people increasingly turn to pharmacokinetic models and estimation of parameters of such models. In this work several parameter estimation methodologies were compared within the context of the most common pharmacokinetic model used in posi...

This study examined the factors that influence agricultural production and exports with specific reference to the natural rubber in India. Secondary data was used for this study. Ordinary Least Squares (OLS) technique was used in analyzing the relevant data. The OLS findings revealed that natural rubber production is significantly (p<0.05) by export of natural rubber (β=0.05), stock (β=0.21) an...

This article deals with a very simple issue: if we have grouped data with a binary dependent variable and want to include fixed effects (group specific intercepts) in the specification, is Ordinary Least Squares (OLS) in any way superior to a (conditional) logit form? In particular, what are the consequences of using OLS instead of a fixed effects logit model with respect to the latter dropping...

Partial least squares (PLS) is sometimes used as an alternative to covariance-based structural equation modeling (SEM). This paper briefly reviews currently available SEM techniques, and provides a critique of the perceived advantages of PLS over covariance-based SEM as commonly cited by PLS users. Specific attention is drawn to the primary disadvantage of PLS, namely the lack of consistency of...

We examine whether hedging effectiveness is affected by asymmetry in the return distribution by applying tail specific metrics to compare the hedging effectiveness of short and long hedgers using crude oil futures contracts. The metrics used include Lower Partial Moments (LPM), Value at Risk (VaR) and Conditional Value at Risk (CVAR). Comparisons are applied to a number of hedging strategies in...

Ridge regression is often the method of choice in ill–conditioned systems. A canonical form identifies regions in the parameter space where Ordinary Least Squares (OLS) is problematic. A curious but unrecognized property of ridge solutions emerges: Under spherical errors with or without moments, the relative concentrations of the canonical estimators reverse as the ridge scalar evolves, the est...

PURPOSE To map health outcome related variables from a national register, not part of any validated instrument, with EQ-5D weights among stroke patients. METHODS We used two cross-sectional data sets including patient characteristics, outcome variables and EQ-5D weights from the national Swedish stroke register. Three regression techniques were used on the estimation set (n=272): ordinary lea...

This study was conducted to examine the hypothesis that organizational commitment and job involvement interact in the prediction of turnover (Blau & Boal, 1987). Prior work in this area has not incorporated a sufficiently broad definition of commitment, has omitted relevant covariates, and has utilized inappropriate estimation procedures (ordinary least-squares regression [OLS]). The presence o...