Mark Dahlke1, F. Jay Breidt1, Jean D. Opsomer1 and Ingrid Van Keilegom2 ... Abstract: Post-stratification is used to improve the precision of survey estimators.
NONPARAMETRIC ENDOGENOUS POST-STRATIFICATION ESTIMATION Mark Dahlke1 , F. Jay Breidt1 , Jean D. Opsomer1 and Ingrid Van Keilegom2 1 Colorado
State University and 2 Universit´e catholique de Louvain
Abstract: Post-stratification is used to improve the precision of survey estimators when categorical auxiliary information is available from external sources. In natural resource surveys, such information may be obtained from remote sensing data classified into categories and displayed as maps. These maps may be based on classification models fitted to the sample data. Such “endogenous post-stratification” violates the standard assumptions that observations are classified without error into post-strata, and post-stratum population counts are known. Properties of the endogenous post-stratification estimator (EPSE) are derived for the case of sample-fitted nonparametric models, with particular emphasis on monotone regression models. Asymptotic properties of the nonparametric EPSE are investigated under a superpopulation model framework. Simulation experiments illustrate the practical effects of first fitting a nonparametric model to survey data before poststratifying. Key words and phrases: Monotone regression, smoothing, survey estimation.
