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.
In the 1999 study kids were found to have spent an average of 6 hours 19 minutes a day with digital media, which the 2010 study showed the amount of time to have increased to 7 hours 38 minutes a day. Kids between the ages of 11 and 14 spent the most time exposed to digital media, 11 hours 53 minutes a day. The youngest kids in this study, those between the ages of 8 and 10, spent an average of 7 hours 51 minutes a day using technology.