A recent study by Adrian Nieto Castro provides new evidence of how television affects children’s learning. The study focuses on a unique event in the UK: the nationwide switch from analogue to digital TV. The transition was implemented by two independent organisations in the communications sector, and happened at different times across regions, creating a natural experiment enabling a study of the causal impact of television on academic performance. To do so, the policy variation was linked to three data sources — academic records from millions of students, information on TV markets, and surveys of children’s daily activities.
In what consisted the digital switchover? Between 2008 and 2012, every TV transmitter in the UK was upgraded to stop broadcasting the old analogue signal and start delivering a stronger digital one. Overnight, households went from just five channels to as many as forty — a huge increase for more than 17 million viewers. Because transmitters across the country were switched over at different times, this created a kind of natural lottery: some neighbourhoods got access earlier than others. This staggered rollout gives an opportunity to carefully study how gaining access to digital TV affected children’s school performance, while providing causal estimates.
To measure the impact on education, the timing of the switchover was linked to detailed records of pupils’ test scores from the UK Department for Education. These records cover nearly the entire population of children in public schools — more than seven million student-year observations between 2006 and 2019. By comparing how test scores changed in areas that got digital TV earlier versus later, the study found that children’s performance improved after the switchover. Four years on, pupils scored noticeably higher in national exams. Importantly, the benefits were concentrated among children from disadvantaged families living in poorer areas.
But why did test scores improve? The mechanisms were explored using TV market data that track how much time children actually spent watching television. After the switchover, kids did spend more time in front of the screen — a clear sign that the new digital channels were attractive. The higher time spent in front of TV also meant that television was displacing other activities in children’s daily routines.
The key question is: what kinds of activities were children giving up when they spent more time watching TV? Insights are given by survey data from young people aged 10 to 15 in the UK. These surveys reveal that risky behaviours are surprisingly common — for instance, nearly one in five children reported drinking alcohol in the past month, and some began experimenting as early as age 11. After the digital switchover, children — especially those from low-income families — were less likely to spend time in these risky social settings or with peers who might have a negative influence. In other words, extra TV time substituted for activities that could be harmful to learning and development.
Taken together, these findings show that media can shape children’s learning in unexpected ways. The findings suggest that new forms of entertainment don’t automatically harm academic performance — their impact depends on what they replace in children’s lives. When extra screen time crowds out risky or unstructured activities, it can actually boost disadvantaged students’ academic performance.
Television and Academic Achievement: Evidence from the Digital Television Transition in the UK – The Economic Journal, Volume 135, Issue 666, February 2025
