Unbiased mean-of-the-ratios estimators

M. R. Espejo & J. Santos Penas
We are offering two expressions of the bias of the sample mean-of-the-ratios and a new unbiased estimator alternative to the Hartley-Ross' (1954) based on the same statistics. From here, it is possible to build some operationally better estimators based on the mean-of-the-ratios statistic.