Many people thinks teens should pay their attention to school,so perhaps your parents refuse to make you work until you turned 18,they feel that as a teenager the primary focus should be going to school, making good grades, and enjoying being a teen while they still can. In fact, as long as you keep the following some rules, you can be successful at being both a student and a worker, however, I think a teen should get a job.
You can learn responsibility. I remember my parents wouldn't buy me a car, give me allowance, or any money. If I wanted it, I had to work for it, and I did. It's not a bad thing, it's a good thing. I loved working as a teen, I made a ton of friends, bought the things I wanted, and stayed out of trouble.
And yet another is that teenagers need to pay some of their own expenses, like for the car or spending money, so they aren't getting used to the idea of mooching off the parents all the time. This can lead to an extended sense of entitlement that they really need to grow out of. A lot of kids today are spoiled and they need to learn to earn, appreciate, and be responsible for money.
Becoming an adult is a process. The reason is, what a lot of people don't realize is that you don't suddenly become an adult at midnight on your 18th birthday. Becoming an adult is a process. It has to start before you're 18, or you'll still be a child when you come of age. Another good reason to work is to understand that if you don't get a college degree, that's the sort of job you can expect to do your whole life. That can be pretty motivating.
Recession is also a reason. As a result of recession, families now have less spending money. Everything is more expensive now so your parents aren't giving you as much spending money. You can save up for college or you have to pay for a car and you also need spending money. Teenagers now need to be thrifty, or produce their own money in order to buy things they want. I read this whole article in TIME about it, and its true. With less money in general, one of the first places hit is the teenagers non earned pocket full of cash.
I think a job for a teen is a great idea. It gives them some extra spending money and they learn the value of a dollar.That being said, it should definitely be monitored. Most jobs will allow them to work on weekends only and they can still get a nice paycheck at the end of the week, or they can work a few hours after school, so long as they still have time to do their homework.
Another good thing is that if a teen gets a job and works hard,they'll be able to have references for future jobs (after high school/college).They would also learn that money doesn't grow on trees and that people have to work hard to get it;they'll learn to save better since they know how hard it was to get it.They can get certain stuff they need without having to ask their parents for it (specially if their family is not at the best economic position).