  The Ewens sampling formula is a distribution related to the random partition
of a positive integer. In this study, we investigate the issue of non-existence
solutions in parameter estimation under the distribution. As a result, the
first and second moments matching estimators to the uniformly minimum variance
unbiased estimator are derived using the Ewens sampling formula in asymptotic
sense. A Monte Carlo simulation study is performed to evaluate the efficiency
of the resulting estimators.
