Weighting for the USDA Forest Service, National Woodland Owner Survey

Abstract

The U.S. Department of Agriculture, Forest Service's National Woodland Owner Survey (NWOS) collects information on the attitudes, behaviors, and general characteristics of private forest ownerships across the United States. An area-based sample design that results in inclusion probabilities proportional to size of forest holdings is used to select ownerships to participate in the survey. In order to make accurate population-level estimates, this sample design must be incorporated into the estimators. In this report, a weighting approach for generating estimates of totals, means, proportions, and quartiles from NWOS data in terms of ownerships and acreages is presented, along with a bootstrapping approach for estimation of the associated variances. In addition to presenting a theoretical justification for the approach, the estimators are validated using data from a fully enumerated population. An R package for implementing the estimators is available on GitHub (https://github.com/familyforestresearchcenter/nwos).