DURHAM, N.H. -- Teenagers from higher-income families are more likely to hold jobs than those from lower-income households, according to University of New Hampshire research that suggests employment itself has become an extracurricular activity.

The university's Carsey School of Public Policy examined the latest numbers from the National Survey of Children's Health, which collects data on about 95,600 children ages 17 years and younger every four to five years. For the report released Tuesday, data was analyzed on about 35,000 children ages 12 to 18.

According to the survey, higher-income youths are twice as likely to be employed as their lower-income peers, a finding that researcher Sarah Leonard said was perhaps surprising since one might expect lower-income youth to have higher employment rates. She said that could suggest that after-school jobs have become a form of extracurricular activity.

"This possibility could explain why rural youth are more likely to work -- if fewer traditional extracurricular opportunities are available in rural areas, employment may serve as a replacement," she said.

Higher-income youth are one-and-a-half times as likely to participate in extracurricular activities, defined as school-based or extramural activities that aren't required by schools or eligible for school credit, including sports, clubs and other structured activity. The reasons for the disparities are unclear, Leonard said, but it's possible that financial costs, eligibility for and availability of activities could be factors. For example, many schools require students to maintain minimum grade point averages to participate in extracurricular activities.

"If low-income youth have lower academic achievement, as some research shows, their opportunity to participate in school-based extracurricular activities will be diminished," Leonard wrote. "In turn, since extracurricular participation is linked to better grades, decreased participation could also lead to poorer academic achievement."

She suggests policy makers and school systems consider changing their eligibility requirements for school-based activities and making participation in such activities more affordable and accessible. She said colleges and universities should also reconsider admissions policies that are heavily influenced by extracurricular involvement.