The City Assembly of Toyoake, Japan, a city with 68,000 residents, recently introduced a rule limiting the use of digital devices to two hours per day outside of work and school. The idea was introduced by mayor Masafumi Kouki. He’s grown concerned that residents, particularly children, have become addicted to digital devices.

The new law has no penalties for exceeding the 2-hour limit, and the government will not be tracking cellphone and tablet usage. The hope is that in a society that has social pressure to follow official guidelines, the amount of device usage will drop.

The City is like much of the Western world, where people heavily use cellphones. A government study last year found that Japanese elementary and secondary school students use their phones on average for about five hours each day. Several recent studies in the U.S. put average usage here at over 4.5 hours per day.

This is not the first time a local government in Japan has tried to curb computer usage. In 2020, Kagawa Prefecture on the Japanese island of Shikoku passed a law limiting the time young people can spend playing video games. That law tried to limit game-playing to one hour per day on weekdays and 90 minutes per day on weekends.

While it has not yet been officially recognized as a psychological diagnosis, youth phone addiction is a growing concern for many health officials. Excess phone usage has been linked to declining grades, social withdrawal, anxiety, and depression.

There is a growing movement in the U.S. to ban smartphones from schools. Schools in more than thirty-five states banned phones last year, with even more this school year.

There have been some controlled studies that measure the impact of banning phones in school. A trial in France of 200 schools showed reduced cyber-bullying and increased social interaction of students. A trial of a ban in middle schools showed a 35% increase in student participation with students “talking to each other again”. A study in Brazil, which introduced a county-wide ban, showed a 35% improvement in mathematics and a 13% increase in Portuguese grades.

A more detailed look at the data shows some interesting trends. The impact seems biggest for middle-school students, who generally struggle at that age with impulse-control. The bans seem to have a bigger impact on grades in high-poverty areas. The bans seem to impact girls a lot more than boys.