Thie is completely the wrong approach. Rather, schools should work to ensure that all kids learn how to use digital devices (not just phones) for their own benefit. If all they see at home is parents or siblings on Facebook, Skype and mobile games, then that's what they'll do too. Schools have to teach for reality, boy try to recreate some unrealistic and nostalgic "how it was in the day". Look at Finland and Estonia, they use technology meaningfully in class and get great results. It's not about using it all the time, but about using it where it fits. Prohibiting phones will just lead to new ways of circumventing the ban, new kinds of conflicts, punishments for kids for living what is today a normal life.
If your only approach is to ban & punish, then those phones in kids' hands will be only used for whatever is the easiest low-value engagement. Teach kids that they can use Wikipedia, ebooks, educational videos, and creative tools to satisfy their interests, look up things from class that they don't understand, work together to make a presentation for class, programme Lego or other robots, practice vocabulary and interact with students from abroad in their second or third language, make little videos about the things they've learned, etc and you'll get great results. Frontal lecture causes distractions because it's fundamentally boring, unengaging and loses half the class. Tech can help - if used right. To give just one reference, out of thousands, see eg the OECD Report on this [1].
Tech can be really disruptive. And it can be a great facilitator for learning. It's about how it's used and whether students learnb to use it creatively, critically and constructively. You won't learn which mushrooms are edible by being kept out of the forest, and neither by being thrown into a forest and told to do whatever. You learn to understand what is edible, harmful, useful, ... if an experienced person that knows how to do so accompanies you in the forest once in a while and shows it, explains it and watches as you try to do it yourself in a real forest that you might encounter. Keeping kids away from phones, or allowing them to do whatever will have the same results - they'll play, eat the harmful mushrooms and fail to see the fantastic opportunities. Accompany them in using their own devices. That's the task of an educator today - teach kids how to live in today's world. Not smartphones every minute of the day, but also not forbidden. Use them were it fits. Show them what role they can play.
Principally, this requires teacher training, adapting curricula and testing, and efforts in particular to make sure no kid is left out. Those from good families with educated parents will mostly learn this through parents or after-school activities, but especially poor/migrant/otherwise low performing students will suffer if you don't make sure education teaches them for the world of today.
Really, really sad. This is a purely ideological move, catering to an older, reluctantly digital voter population. But it is also a betrayal of the very kids it claims to help.
[1] http://www.oecd.org/publications/students-computers-and-lear...
