In migrant-sending rural China, mobile phones sit at the center of a development dilemma. They can sustain family ties and widen access to information, yet they may also erode the daily routines through which foundational skills are built. Using four waves of panel data from rural boarding schools in two provinces (2015–2017, 2020), this study examines whether children’s phone use is linked to learning outcomes and how that link operates in low-resource contexts where adult supervision and alternative learning inputs are limited. Two-way fixed-effects estimates show that within-student adoption of mobile phone use is followed by lower reading achievement in late primary school and a lower probability of scoring above the median, net of rich time-varying controls. Supplementary analyses of sleep, reading engagement, and attention-related outcomes, estimated within the same fixed-effects framework, suggest patterns consistent with routine-displacement pathways, particularly reduced sleep, weaker reading engagement, and lower sustained attention. Associations are stronger for boys and are concentrated among children living with parents, whereas estimates for left-behind children are smaller and less precise, consistent with phones also serving compensatory relational functions under parental migration. Early and sustained exposure in primary school further predicts lower standardized middle-school exam performance in 2020. The findings highlight feasible school and caregiver strategies that protect sleep and study routines while preserving supportive communication uses in migrant-affected rural communities. • In migrant-sending rural China, mobile phones reshape time use in low-resource schools. • Phone use is linked to lower learning outcomes across primary-school waves and into middle school. • Sleep and reading routines, not broad health measures, are key observed pathways. • Risks concentrate among boys, while left-behind children show a different profile. • Findings inform school and family strategies for equitable human-capital development.
Li et al. (Fri,) studied this question.