Gradient Identification and Institutional Responses to the Risk of Sexual Abuse of Left-Behind Minors: An Empirical Analysis Based on 187 Judicial Cases in Eastern Sichuan

Based on 187 judicial cases involving sexual abuse of left-behind minors in eastern Sichuan (2021–2025), this study employs binary logistic regression, interrupted time series (ITS) analysis, and event history analysis to examine the effects of absent guardianship, acquaintance networks, and the mandatory reporting system on the risk of abuse. The study found that for every one-level increase in the degree of guardianship absence, the risk of repeated abuse increased by 67.3% (odds ratio [OR] = 1.673, p = .001); the recurrence rate of abuse by acquaintances who are not immediate family members was significantly higher than that by strangers (OR = 2.76, p = .003), while no significant difference was observed for immediate family members; the time lag in reporting abuse within the family was significantly longer than that for abuse outside the family (8.7 months vs. 4.2 months, t = 11.67, p < .001); following policy implementation, the proportion of cases reported by obligated parties rose from 25% to 81.5%, but a low baseline confounded the ITS estimate due to the pandemic (β 2 = 12.6), and the stock of risk did not decrease significantly. This study preliminarily reveals a conditional association between the risk effects of familiar-person networks and the completeness of guardianship, offering directional insights for extending the social ecosystem theory to a “family–community cross-level risk transmission mechanism.”