A Note on a Semiparametric Estimator of Mortality
本文讨论了Hearn等人提出的死亡率半参数估计量可能出现的非正态渐近行为，并指出其在实际应用中导致的困难。
A semiparametric estimator of natural mortality, introduced by Hearn, Sandland & Hampton (1987), was studied by Leigh (1988), who noted that its asymptotic variance may sometimes be infinite. We discuss the nonnorrnal asymptotic behaviour that can occur in this case, and remark on difficulties that it causes in practice.