Keyfitz N
Demography. 1977 Nov;14(4):411-8.
The immediate effect of discovering a way to cure cancer would be a reduction in the number of deaths in the United States by the number of people now dying from that cause. Within a short time, however, deaths from other causes would increase, and the net long-term effect would be relatively small. A parameter is derived that measures how much the expectation of life is increased by a marginal reduction in any cause of death. That parameter is additive in the several causes and has other advantages, though it does not avoid the assumption of independence.
找到治愈癌症的方法所产生的直接影响将是美国因癌症死亡的人数减少,即现在死于该病因的人数。然而,在短时间内,其他病因导致的死亡人数将会增加,长期的净影响相对较小。推导出一个参数,该参数衡量任何死因的边际减少会使预期寿命增加多少。该参数在多种病因中具有可加性且有其他优点,尽管它并未避免独立性假设。