csurvey: Implementing Order Constraints in Survey Data Analysis

Recent work in survey domain estimation has shown that incorporating a priori assumptions about orderings of population domain means reduces the variance of the estimators. The new R package csurvey allows users to implement order constraints using a design specified in the well-known survey package. The order constraints not only give estimates that satisfy a priori assumptions, but they also provide smaller confidence intervals with good coverage, and allow for design-based estimation in small-sample or empty domains. A test for constant versus increasing domain means is available in the package, with generalizations to other one-sided tests. A cone information criterion may be used to provide evidence that the order constraints are valid. Examples with well-known survey data sets show the utility of the methods. This package is now available from the Comprehensive R Archive Network at <http://CRAN.R-project.org/package=csurvey>.