This Bulletin explores the strengths and weaknesses of six possible explanations for the decline by using data from a number of different sources aggregate data from the National Child Abuse and Neglect Data System (NCANDS); detailed child protective service data from Illinois, Minnesota, Oregon, and Pennsylvania; and self-report data from the National Crime Victimization Survey (NCVS) and from schoolchildren in Minnesota. It provides substantially more evidence about the decline than was available in a previous Bulletin on the same topic.