Combining samples in small area estimation: An application to poverty mapping in Vietnam

Small area estimation (SAE), which combines a population census and a sample survey, is widely used to estimate poverty and welfare indicators in small areas. A common situation in practice is that a population census is conducted using both short- and long-form questionnaires. The short form is used to collect basic demographic information for the whole population, while the long form is used to collect additional information, such as employment, from a random sample. This study shows that combining both short- and long-form data can improve estimation efficiency. This method is applied to poverty maps for the 2014–2019 period in Vietnam.