A UMPU test for comparing means of two negative binomial distributions

A common problem in the biological sciences is to compare the means of two populations of count data. This paper introduces an uniformly most powerful (UMP) unbiased test for testing the equality of means for independent samples of count data from two negative binomial populations in the presence of a common dispersion parameter. The size and power of the UMP unbiased test is compared to several other known tests. The proposed methodology is illustrated with an application to real data.