Kara Rowells enjoys hard work. The native of Tarpon Springs, Florida learned to love being busy from her father.

　　"My dad ... always had a lot of different jobs at once, and so that's the model that I saw," she told VOA. "My dad will often work a job all day ... and then go to another job at night. ... It wasn't a crazy concept for me."

　　So when Rowells began studying at Bethune-Cookman University in Daytona Beach, Florida in 2008, she was more than happy to support herself. Her parents gave her a little financial assistance. But she covered most of her education costs with loans and her own income.

　　At first, Rowells worked part-time as a teacher for very young children. But she says the average pay for workers in that field in Florida is very low. So she took on other teaching positions to make more money.

　　In 2010, she decided to change schools. She began studying theater performance at Florida Agricultural & Mechanical University in Tallahassee – also called Florida A&M. And she took on more jobs. She began teaching dance, as well as taking care of children.

　　But changing schools slowed her progress toward a degree. To speed it up, Rowells had to take more than six classes in one term. In addition, she was working between 10 and 45 hours each week at her jobs.

　　Always being busy would often cause her to feel stress and miss sleep, Rowells says. And, she says, she was not able to enjoy many of the social experiences involved in American higher education.

　　But Rowells was able to finish her study program as planned in 2012. She even earned a graduate degree from Florida State University in 2015 while working just as much as she had as an undergraduate.

　　The most difficult part of her college experience, Rowells says, was learning that despite all her hard work, she still owed about $100,000 in student debt. She does not regret how much or how hard she worked. But she does feel her experience offers some valuable information about balancing work and studies that many college students could use.

　　College students should know their worth, Rowells says. And they should avoid sacrificing other parts of their lives for work if they can.

　　What the research says

　　The majority of students at colleges and universities in the United States work while they study. And, the amount that students are working while studying is increasing. Also, the more hours college students work outside their studies, the more harm they may be doing to their academic success.

　　In 2015, the Georgetown University Center on Education and the Workforce reported on the state of working college students. The center found that 70 percent of all U.S. college students have a job while they are enrolled in school.

　　Many of these students are putting a lot of hours into their jobs. The center found that almost half of undergraduates work more than 30 hours per week. And one-quarter of students study full-time while working full-time – at least 40 hours a week.

　　Nicole Smith is the chief economist for the center. She says the numbers of students working – and the numbers of hours they work have all increased over the past 30 years.

　　One reason is that the cost of college in the U.S. has increased greatly in that time. However, that is not the only reason more college students are working more hours.

　　Smith notes that even students whose families can afford to support them are working while they study. That is because employers are expecting more and more out of college graduates, including work experience, she says.

　　"Employers are less likely to want to train their workers for the job traits ... that you would not necessarily learn within a college setting," she told VOA. "Employers are expecting, by the time you ... walk in ... that you can do exactly what they expect you to do, and ... you have all of the experience necessary, so that you can be a 100 percent productive employee from day one."

　　Smith admits that research shows working up to 15 hours a week can be helpful for college students. It can improve their time management skills, for example. But when students work more than that, they risk more than just missing out on social events, as in the case of Rowells, she says. With students' attention split between work and class assignments, their performance in both areas will suffer.

　　The ACT Center for Equity in Learning is an organization that studies education in the United States. In August 2017 it reported that working more than 15 hours a week can seriously limit college students' ability to complete their study programs.

　　The ACT Center's research showed that working more than 15 hours affected both high- and low-income students similarly. It reported that just 57 percent of high-income students who worked more than 15 hours weekly completed their study programs in six years. Only 41 percent of low-income students who worked more than 15 hours a week completed their programs in the same time.

　　In comparison, college students from either income level who worked under 15 hours were nearly 20 percent more likely to finish in six years than those who worked more.

　　Professor Laura Perna suggests that a big part of the problem is that over-worked college students do not have the time to seek help. Perna teaches in the University of Pennsylvania's Graduate School of Education. She is also the executive director of the Alliance for Higher Education and Democracy.

　　Perna notes that there are only so many hours in the day. Students with jobs do not often have the time to make use of the support services schools offer, such as academic and financial advising.

　　"When those offices are only open a certain number of hours," she told VOA, "students who are working ... may find it more difficult to access those really important services that they need in order to make timely ... progress to their degree."

　　Perna and Smith agree that as older Americans increasingly seek higher education, working college students will become more common. These older students will likely not have parents' financial support, and may even be supporting other people themselves.

　　In addition, Perna and Smith point out, first-generation and low-income students of any age are more likely to pay for their education by working. They often choose to do so rather than by taking out larger loans.

　　As the student population changes, Perna and Smith say, U.S. colleges and universities will need to consider how they advise their students and serve their changing needs.

　　I'm ­Pete Musto. And I'm Dorothy Gundy.

　　Pete Musto reported this for VOA Learning English. Kelly Jean Kelly was the editor. We want to hear from you. How common is working full-time while studying full-time in your country? How do you think working more than 15 hours per week might affect you while you seek a college education? Write to us in the Comments Section or on 51VOA.COM.