DS-optimal designs in one way ANOVA

Characterization and construction of optimal designs using the familiar optimality criteria, for example A-, D- and E-optimality are well studied in the literature. However the study of the Distance Optimality (DS-) criterion introduced by Sinha (1970) has very recently drawn attention of researchers. In the present article, we consider the singularly estimable full rank problem of estimating the full set of elementary treatment contrasts using the DS optimality criterion in the set up of a one way ANOVA model. Using a limit argument it turns out that a CRD in which difference between any two allocation numbers is at the most unity is uniquely DS-optimal. Acknowledgement. We are thankful to Prof. B. K. Sinha for suggesting the problem to us and many helpful discussions with him. We are also thankful to the referees for drawing our attention to the reference of Bischoff (1995) and many helpful comments.     

The Effect of Concept Formulation on Concept Test Scores

While concept testing is a mainstay of the new product development process, there is little empirical evidence on the variation in consumer responses due to alternative concept formulations, particularly for those tests undertaken early in the product development process. The present study addressed this gap in the literature by using a split sample mail survey to compare stripped, embellished, and visual concept formulations for five heterogeneous product concepts. It was found that respondents' answers to attitude and purchase intention questions showed only minor variation with different formulations of the concept test statement. It also was found that the ranking of the concepts showed no substantial changes across the different formulations. Therefore, the type of concept statement formulation may not be that important, at least for early ranking tasks performed before experiential prototypes are available. Early concept tests therefore may be carried out using stripped concept statements. This may reduce costs, allowing organizations to undertake early concept testing more frequently across a wider range of products.     

Budget deficits and real interest rates: Updated empirical evidence on causality

Using error-correction model (ECM) estimation, the paper empirically examines the causality relationship between the federal government budget deficit and the ex ante real interest rate yield on high grade long term tax free municipal bonds in the U.S. To clarify this deficit or interest rate relationship, the budget deficit is measured by the primary budget deficit, which excludes net interest payments by the Treasury. In a model that includes federal personal income tax rates and net international capital flows, as well as money supply growth, the ECM estimates strongly suggest a bi-directional relationship between the primary budget deficit and the ex ante real interest rate yield. Budget deficits apparently do matter! William Simon's concerns were justified.The author is indebted to P. A. V. B. Swamy for ideas and helpful suggestions and Will Perry for data assembly and processing.