Small area estimation is any of several statistical techniques involving the estimation of parameters for small sub-populations, generally used when the sub-population of interest is included in a larger survey. The term ‘small area’ in this context generally refers to a small geographical area such as a county. It may also refer to a ‘small domain’, i.e. a particular demographic within an area. If a survey has been carried out for the population as a whole (for example, a nation or state-wide survey), the sample size within any particular small area may be too small to generate accurate estimates from the data. To deal with this problem, it may be possible to use additional data (such as census records) that exists for these small areas in order to obtain estimates.
Small Area Estimation (SAE) google