In pricing theory, the scarcity principle suggests that the price for a scarce good should rise until an equilibrium is reached between supply and demand. However, this would result in the restricted exclusion of the good only to those who can afford it.
Children aged between three and seven should be limited to half-an-hour to an hour of screen time each day, he said. Those aged seven to 12 should spend just one hour in front of screens. Children aged 12 to 15 should have a maximum of 1.5 hours in front of screens and those aged 16 and over should spend just two hours, he recommends. ''Reducing total daily screen time for children, and delaying the age at which they start, could provide significant advantages for their health and wellbeing,'' he writes.
The average 10-year-old has at least five screens readily available to them at home, and over the course of childhood youngsters spend more time watching TV than they spend in school, he said. Limiting the amount of time children spend in front of a screen could have significant advantages for their health and wellbeing, Dr Sigman said. The population's vast use of games consoles, tablet computers, televisions, smart phones and laptops has been linked to obesity problems and an increased risk of cardiovascular disease and Type 2 diabetes, he warned.