As the school year draws to a close and fewer teens plan to spend their summers scooping ice cream, carrying golf clubs and working other hourly jobs, parenting and career counseling experts say today's young people are forgoing valuable life and workplace lessons needed to become successful and happy adults.

"When I think about kids en masse not working, I think about all the things they're going to miss out on," said Tim Thayne, a family therapist and author of the book "Not by Chance: How Parents Boost Their Teen's Success in and After Treatment."

"There's a level of accountability that doesn't come with internships; it doesn't come with service either," he said. "If you're out doing a service project, the person you're doing the service project for probably isn't going to get after you if you're on a cellphone."

The youth summer labor force — the number of 16- to 24-year-olds working or actively looking for work — has been on the decline for more than 30 years, with a peak rate of 77.5 percent in July 1989. In 2017, the youth labor force participation rate was 60.6 for July, considered the peak of summertime youth employment, according to statistics from the U.S. Department of Labor.

Last July, only four in 10 teens were in the labor force, compared with about seven in 10 in July 1978, according to the department.

Research points to a number of factors that have contributed to the decline in teens taking summer jobs: more students taking internships or seeking volunteer experiences to bolster college applications, overbooked extracurricular activity schedules, and lack of available hourly jobs in some communities.

But Mike Minton, assistant director of the Career Center at Illinois State University, said he and other college officials think teens avoiding summer jobs in the hopes of padding their college résumés is counterproductive. College officials sometimes value work experience just as much, if not more, than service in a community.

"We see the value the students bring when they bring employment experience from high school," Minton said, adding that students with notable work experience from their teen years often come to college with a strong sense of time management, strong verbal communication skills and a good work ethic.

Students who work summer jobs before college also seem to get exposure to lines of work they may or may not be interested in, making it easier to narrow down a career choice later, Minton said.

"Getting used to the flow of work, getting used to customer service at a fast-food restaurant or up in the hay loft, it's great for just character development," Minton said.

Thayne said allowing teens to be employed by an outside business or person is most beneficial because it forces them to show respect, develop relationships and be compensated by people they've never met. But he said parents have a responsibility to help a child seek out those opportunities.

In working with families, Thayne said, he encourages parents with teens to balance allowing young people to experience situations that build resilience while also keeping them from too much difficulty for their age.

"Your goal is to help them someday be happy and be able to be a great, contributing member of society," Thayne said.