A comparison of pivotal sampling and unequal probability sampling with   replacement
  We prove that any implementation of pivotal sampling is more efficient than multinomial sampling. This property entails the weak consistency of the Horvitz-Thompson estimator and the existence of a conservative variance estimator. A small simulation study supports our findings. 
Guillaume Chauvet (ENSAI, IRMAR), Anne Ruiz-Gazen (TSE)
math.ST stat.AP stat.ME stat.TH