The paper sketches a proper statistical setting necessary to define the sampling design for Small Area Estimation (SAE). Since SAE techniques are commonly used in official statistics, relying on appropriate sampling designs to improve the quality of estimates becomes crucial. The sampling design is based on both allocation and sampling selection. The allocation step solves a non-standard problem necessary for finding the minimum-cost solution that controls the accuracy of the model-based small area estimator. The sampling selection ensures the planned sample sizes for each level of random effects affecting the variables of interest.
Falorsi et al. (Tue,) studied this question.