This tutorial describes the use of the TWANG package in R to estimate propensity score weights when there are two treatment groups, and how to use TWANG to estimate nonresponse weights. Specifically, it describes the "ps" function (which stands for Propensity Scores), the proper syntax for using the function, and the features the function contains.
This report is part of the RAND Corporation tool series. RAND tools may include models, databases, calculators, computer code, GIS mapping tools, practitioner guidelines, web applications, and various toolkits. All RAND tools undergo rigorous peer review to ensure both high data standards and appropriate methodology in keeping with RAND's commitment to quality and objectivity.
Permission is given to duplicate this electronic document for personal use only, as long as it is unaltered and complete. Copies may not be duplicated for commercial purposes. Unauthorized posting of RAND PDFs to a non-RAND Web site is prohibited. RAND PDFs are protected under copyright law. For information on reprint and linking permissions, please visit the RAND Permissions page.
The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.