Efficient family of estimators of median using two-phase sampling design

ABSTRACT

For a trivariate distribution, an efficient family of estimators of median of study variable using the known information on the auxiliary variables has been proposed under two-phase sampling design. The expressions for bias and its mean square error have been obtained up to first order of approximation. It has been shown that the proposed estimator has smaller bias as compared to estimator defined by Singh et al. (2006 Singh, S., Singh, H.P., Upadhyaya, L.N. (2006). Chain ratio and regression type estimators for median estimation in survey sampling. Statist. Pap. 48:23–46.[Crossref], [Web of Science ®] , [Google Scholar]) with the same efficiency. The results have also been illustrated numerically by taking data from different populations considered in literature.     

Reconstructing the Sikh Diaspora

The Sikh diaspora, along with the Jewish Diaspora, is perhaps one of the only religious diasporas in the world. The Sikhs are scattered across the globe today. This article is an attempt to outline the reasons for Sikh migration out of Punjab and the role played by the colonial rulers in that migration. It traces the process of migration of Sikhs and their emergence as a diaspora.     

Gender Differences in Policy Preferences: A Summary of Trends from the 1960s to the 1980s

Using 267 repeated policy questions (962 time points), we examinegender differences in policy choices and how they have changedfrom the 1960s to the 1980s. The average gender difference inpreferences toward policies involving the use of force haveconsistently been moderately large. Sex differences in opiniontoward other policies—regulation and public protection,"compassion" issues, traditional values—have been approximatelyhalf as large but they also warrant more attention than in thepast. Our analysis suggests that the salience of issues hasincreased greatly for women, and as a result differences inpreferences have increased in ways consistent with the interestsof women and the intentions of the women's movement.     

Knowing What Your Customer Wants: Improving Inventory Allocation Decisions in Online Movie Rental Systems

In Online Movie Rental Systems, customer desire to rent can often be observed before the actual consumption occurs. Desire represents uncensored (or true) demand information. Hence, the impact of inventory decisions (numbers of physical copies of different movies) can be accurately traced to the creation of desire (via Word‐of‐mouth), and then to rental. Word‐of‐Mouth (WOM) has been recognized as one of the most influential sources of information transmission, especially for experience goods. Poor inventory decisions may result in lost rentals in two ways: One is the loss of rentals because of low inventory (direct effect), and the other is the loss of the possible demand (rentals) that could have been created through WOM (indirect effect). We use data from an online DVD‐by‐mail firm to estimate the direct and indirect effects of inventory decisions, considering the circular relationship: Rental generates WOM, WOM creates Desire, and Desire turns into Rental. We find that the magnitude of indirect effects is significant, comparable to and sometimes even exceeding direct effects. The value of the empirical findings to facilitate better inventory allocation decisions is examined.