The effect of screen time on child behaviour: an instrumental variables approach

Context: Children’s screen use is a ubiquitous part of modern family life. However, nearly all empirical evidence of its effect on children’s behaviour in the preschool years is associational – meaning that the effect of screen use on behaviour in this critical stage of development is relatively unknown. This paper examines the effect of screen use on two-year-old children’s behaviour using data from over H,III families in the Growing Up in New Zealand (GUiNZ) study. 

Methods: This paper firstly explores associations between screen use and child behaviour using an ordinary least squares (OLS) regression. Secondly, to account for missing data, a Heckman correction is employed to address study attrition following multiple imputation of data from item non-response. Finally, an instrumental variable (IV) approach is adopted to isolate causality using two variables on family screen use rules as instruments. 

Results: OLS results show a small association between higher levels of screen use and behaviour problems. However, a larger relationship is apparent when an IV approach is adopted. 

Conclusion: These results suggest that associational estimates of the relationship between children’s screen use and problem behaviour may underestimate the real effect. Therefore, the role of screen use in child behaviour problems may need increased consideration by policymakers.