The effect of TV viewing on children’s obesity risk and mental well-being: Evidence from the UK digital switchover
利用英国数字电视转换这一外生事件，研究发现电视观看增加显著提高了儿童心理健康困难评分，并可能增加BMI，原因在于减少了社交和体育活动参与。
We examine the effect of screen-based activities on obesity and mental well-being for children, using a large survey dataset representative of the UK population and an event study model that exploits exogenous variation in the entry date of the digital television transition in the UK. The digital transition increased the number of available free television channels from 5 to 40, leading to a rise in television viewing time. Our results show that receiving access to digital television signal considerably increases the mental health total difficulties score among children, and that this impact grows over time. We also find suggestive evidence that the digital transition could have increased BMI for children. Underlying the net effects appear to be decreases in participation in social and physical activities.