Why? I'm 30+ and I hate it when my nephew spend all his time in front of his screen..
Let's start with "Every child should have food and a home." Until we manage that, i see no point in getting luxury items.A phone is just a way to communicate, it can create the illusion of safety but also become a safety risk, since it can allow strangers to communicate with kids without their parents noticing.
I see why some people want them for their kids in the case of emergencies but I don't think it's absolutely necessary. Plus, I agree with @anna's point
I wonder if mobile phones do us (both adults and children) more harm than good.
Children are vulnerable, there's no doubt about that. For any lost/stuck child to be able to contact an adult authority at any time is a good thing. Think of the kids who are starving in third world countries! They don't need the internet, or all the gadgets that modern phones have, they need a way of saying "I'm too hungry to walk, can you come and help me?"A telephone, is not a luxury item. Yes, food and home comes first, but communication should definitely come next. Heck, every adult should have a phone also.
I think that when you turn 14 you should get a phone. Not necessarily a smart phone, however.