The effective sample size, also defined by Kish in 1965, is the original sample size divided by the design effect.Kish, Leslie, and J. Official Stat. "Weighting for unequal Pi." (1992): 183–200. (pdf link) This quantity reflects what would be the sample size that is needed to achieve the current variance of the estimator (for some parameter) with the existing design, if the sample design (and its relevant parameter estimator) were based on a simple random sample.
