It was just about a year ago that Saba Ghahari took her parents' advice and made a crucial decision about her education.
She decided against working part-time during the school year - passing up the extra cash - so she could concentrate on her grades instead.
Ms. Ghahari, who is now 18, was entering Grade 12 at Stoney Creek, Ont.'s Orchard Park Secondary School and had dreams of going to university and eventually becoming a dentist.
"I wanted to find a job but my parents told me not to have a job during the school year," she says. "Grade 12 is the most important year for grades and they wanted me to focus on my marks instead."
It's a choice few students make: About 65 per cent of high-school students who can work part-time do. And with those jobs, school, homework and extracurricular activities, Canadian teens are busier than ever, according to The Busy Lives of Teens, a 2007 Statistics Canada study. The study shows Canadian kids work more during the school week than teens in nine other European and North American countries.
But experts disagree on whether that load should include a part-time job. Some say doing so gives teen much needed maturity in the work force, helps build a work ethic and improves organizational skills, as well as providing spending money. Others say it distracts students from their real job - learning and getting good grades.
Jorgen Hansen, an associate professor of economics at Montreal's Concordia University, decided to look into whether teens' part-time job affects grades. He used data from Statistics Canada's Youth in Transition Survey - which follows cohorts of students over a number of years.
In comparing work and grade-point averages, Dr. Hansen concluded that working part-time hurts grades. The more you work part-time, the greater the harm to grades.
Another finding: the younger a teen, the greater the detrimental impact. At 15, teens just don't have the same maturity and organizational skills that they would at 17.
"I'm a parent myself, although they're not in school yet," Dr. Hansen says, "I would not encourage my kids to work. And if they do want to work, if they insist on doing it, I would keep it to a minimum."
But his survey also has a surprising twist: When students participate in school activities, the impact is beneficial - no matter how much time they spend on them.
Alex Usher, a Toronto-based higher education consultant, says the question of whether to work part-time comes down to who the kids are and how to balance their goals. "If you're trying to get 90s and 95s in high school, it's very difficult to combine that with paid work."
Judging an individual child's maturity level and ability to organize is crucial for parents, Mr. Usher says. Smart teens know what they can and can't handle and won't work more than they should. For others, taking on too much can be detrimental.
Wendy Patton, a dean of the faculty of education at Queensland University of Technology in Brisbane, Australia, is an advocate of kids taking part-time jobs, but she agrees that moderation is important.
Dr. Patton says her research shows that part-time work benefits most students - as long as teens don't work more than 12 hours a week.
She surveyed kids in Year 10 to Year 12, and found that working taught teens skills they didn't necessarily learn at school - knowledge of the workplace, how to work for other people, teamwork and time management.
"Students have a greater confidence in their own ability to do a range of things when they work," she says. "They have a greater confidence in things like time planning, working with adults; they have a greater confidence in their ability to make decisions."
One added benefit: Working helps teens become aware of the benefits of staying in school.
"When they've been washing dishes or working in a fast-food place, they start thinking more about what it is they really want to do," Dr. Patton says.
Diane Pacom, a professor of sociology at the University of Ottawa who specializes in youth, says students feel intense pressure to work part-time so that they have money to buy the clothes and technology that their friends have.
"It's really easy to say no, no, no, they should focus on their studies, but let's face it, it's impossible in a society like ours for a teenager to exist without [a part-time job]
"Kids are condemned to work unless they're from a family that can give them everything."
And according to Kathleen Gallagher, a professor at the Ontario Institute for Studies in Education, once students take a job, it can take over: They feel expendable, so when the boss keeps asking for more - an extra night or two a week - they can't bring themselves to say no.
Ms. Ghahari can relate: She tells the story of a friend who worked last year at a fast-food restaurant. Her boss kept giving her more and more hours, even during exam week. "She would pull all-nighters before an exam, and she'd come in and be so tired."
Ms. Ghahari was busy enough. Instead of working part-time, she concentrated on her school work and volunteering - and signed up for a slew of other activities. She volunteered at a dialysis centre at a hospital, where she says she confirmed to herself that she wanted a career in health care. She was a Grade 12 representative at student council, a prefect and a mentor to Grade 8 students. She was in a school play and joined Stop Tobacco at Orchard Park.
In a few weeks, she will be attending the University of Western Ontario to study biomedical science. The next step, she hopes, will be dentistry school.
But this fall, Ms. Ghahari plans to work, this time out of necessity.
"I have to. I have to start working to pay off my student loans."