O'Brien R M, Stockard J, Isaacson L
University of Oregon.
AJS. 1999 Jan;104(4):1061-95. doi: 10.1086/210136.
In the past decade, young people in the United States have been two to three times more likely than in the two previous decades to commit homicides, while those 25 years and older have been less likely to commit homicides than were members of their age groups in the earlier time period. These changes in youth homicide rates are associated with two cohort characteristics that are theoretically linked to criminality: relative size of cohorts and the percentage of cohort member born to unwed mothers. These effects persist throughout the life span, are independent of age and historical period, and can explain fluctuations in homicide arrest rates before the recent upturn.
在过去十年中，美国年轻人实施杀人行为的可能性是前两个十年的两到三倍，而25岁及以上的人实施杀人行为的可能性则低于早期同年龄段的人群。青少年杀人率的这些变化与两个理论上与犯罪有关的队列特征相关：队列的相对规模以及非婚生育的队列成员百分比。这些影响贯穿人的一生，与年龄和历史时期无关，并且可以解释最近上升之前杀人逮捕率的波动。
