Estimación bajo no-respuestas aleatorias al usar diseños de probabilidades desiguales.
Singh-Singh (1979) considered the nonresponses as generated by a mechanism which is equivalent to simple random sampling (srs). They proposed an estimator under the hypothesis associated. It is unbiased and its variance is a function of an unknown parameter. An approximate expression of its variance is presented in this paper. The robustness of the estimator, if the nonresponse mechanism is not fixed by srs, is characterized when the correct approach is related with the need of subsampling the nonresponse...