Dear Dr. Wes and Katie: I’ve always heard students benefit by working up to 20 hours per week. Is that still true?

Dr. Wes: This question comes from our Twitter feed for parents, @wescrenshawphd. We also have one for teens,

@DrWes4Teens. You can follow our advice and submit questions on either one.

There are two schools of thought on this. Katie makes an excellent case favoring school over work. However, a great deal of teen free time is not spent in the pursuit of greater learning. There’s nothing wrong with free time, but most teens have a significant amount of it, some of which might be better spent by joining the economy. That ancient adage about idle hands and the devil is never truer than in 10- to 20-year-olds.

Moreover, a great portion of today’s high school students will never complete a traditional four-year degree for which much of the advanced high school curriculum is designed. They’ll go to trade school or learn a career on the job. For those teens, high school employment is crucial because it establishes a work history that forms a basis for future career, just as advanced placement classes create a platform for the college-bound.

While a job is no substitute for a high school curriculum (read: stay in school!), it’s an important adjunct that should be encouraged.

As with all things in life, balance is everything, and for teens, striking a reasonable one is an emerging developmental task. Parents can help kids think long-term about how work, high school, college, social life and career combine to bring about an effective young adult. Sometimes that’s a conversation and other times a demand, particularly if one area of life is suffering because of another.

Throw in some financial wisdom while you’re at it. Teens with earned disposable income often struggle as young adults when called upon to spend their hard-earned cash on necessities.

So in the end, 20 hours a week is not a magic number. For some kids, that’s a bit high. Others can probably handle it, if it’s coming out of their free time and not their study time, and if it doesn’t interfere with sleep.

Katie: I would estimate that the majority of teenagers work for at least a few hours every week, whether they’re delivering pizza or ordering it for the kids they baby-sit.

I’m in the minority as a nonworker, but I can certainly appreciate the two big boons teenagers get out of employment: money and responsibility.

But as profitable as those multifaceted earnings can be for teenagers and their parents, it’s important to remember that being a student is already a full-time job.

The average teenager is in school seven hours a day, five days a week. After the bell rings at 3 p.m., students are encouraged to participate in extracurricular clubs and sports. When they get home, it’s time to knock out some assignments and study for upcoming tests. It’s usually suggested that high school seniors spend about two hours studying every night. (That number rises with advanced and AP classes.)

So school commitments can eat up about 10 hours out of a teen’s day, starting at 8 a.m. and ending at around 6 p.m. Trying to fit a 20-hour workweek into that agenda would require long weekend hours and late nights — and that’s without some much-needed down time.

When planning for a job, teenagers and their families should consider their priorities, keeping in mind that the more teens work, the less time they’ll have for sleeping, studying and relaxing. Parents may have to ease up on their academic expectations if their kids are working several hours after school.

That said, the best way to learn the true value of money is by earning it, and that’s what I regret most about not having a job myself.

The purpose of adolescence is to evolve from child to adult — in other words, from play to work. Holding a job for a few hours a week is a good way to initiate that process, but there’s a fine line between working and being overworked.

Teens aren’t adults just yet. We still need some time to be kids.