McDaniel C K, Hammel E A
Demography. 1984 Feb;21(1):41-51.
A relation is shown between r and the ratio (S) of those living who are youngest in their sibsets to those who are oldest. This extends Goldman's work on the relation between r and the ratio (Z) of younger to older ever born sisters. Solved for r, these relations provide kin-based measures of r. Tested against microsimulated population data, the S-based measure, though working from fewer observations per population, performs as well or better than any Z-based measure. Since the data needed to compute S make considerably fewer demands on respondents' knowledge, the S-based measure appears preferable in actual application.
r与同胞组中最年轻者与最年长者的比例（S）之间呈现出一种关系。这扩展了戈德曼关于r与曾经出生的姐妹中年轻者与年长者的比例（Z）之间关系的研究。通过求解r，这些关系提供了基于亲属关系的r度量。针对微观模拟的人口数据进行测试，基于S的度量尽管基于每个群体的观察值较少，但表现与任何基于Z的度量一样好或更好。由于计算S所需的数据对受访者知识的要求要少得多，基于S的度量在实际应用中似乎更可取。
