Fresh Start wood and metal shop teacher Ken Talley, left, looks over the work of student Donnell Mitchell, 18, of Capitol Heights, as he applies polyurethane to an Adirondack chair during class in Washington. (Amanda Voisard/The Washington Post)

The GED was designed to give high school dropouts a second chance at higher education and a good job. But every year, hundreds of thousands of teens take the test before their former classmates have graduated, prompting concerns that too many young people are pursuing a GED before they have exhausted their first chance at a more valuable diploma.

Some economists and educators are calling for stricter limits on access to the GED for younger teens. A growing body of research shows that very few GED test-takers go on to earn a higher degree, and most fare about the same in the workplace as dropouts who don’t pass the exam.

“We are making it easy for them to make a mistake,” said James Heckman, a Nobel-Prize winning economist at the University of Chicago who has studied the impact of the GED. He said easier access to the test induces students to drop out of high school.

According to a 2011 report by the GED Testing Service, about a quarter of test-takers across the country are between 16 and 18 years old, an average that is reflected in both Maryland’s and Virginia’s statewide numbers.

But a Washington Post analysis found significantly higher rates of young test-takers in Prince George’s County, with nearly one in three GED test-takers there last year younger than 18, according to state data. In Montgomery County, one in four was younger than 18. There were far fewer under-18 GED candidates in the District and in Northern Virginia, where the minimum age to take the test without a waiver is 18.

As pressure mounts for the nation’s high schools to increase graduation rates, the GED is drawing new scrutiny. The test is undergoing its largest overhaul in 70 years to align with the more rigorous demands of colleges and employers. And more school systems are devising flexible ways to keep struggling students in school however they can.

Maryland law allows students to drop out of school at age 16 without parental consent — and it also allows them to take the GED at that age — though lawmakers last year voted to raise the age of compulsory education to 18 by 2017. Maryland also offers people who pass the GED an actual high school diploma, rather than an equivalency diploma, which some say is another reason more teens decide to pursue it.

The high rate of younger test-takers in Prince George’s County is “an area of concern,” said Patricia Tyler, director of adult education and literacy services for Maryland’s Department of Labor. “It’s always a concern when young people are leaving school prior to graduation in large numbers.”

But she said there are many complicated reasons teenagers drop out of school. They might fall behind in credits because their home lives are unstable or because of poor health or pregnancy. When traditional schools don’t meet their needs, a GED provides a valuable opportunity to help them take the next step, she said.

Fahirah Jackson was in the ninth grade when her brother was incarcerated on a drug charge, sending her family into a tailspin. They lost their house and moved five times in one year. Jackson dropped out of Charles Herbert Flowers High School in Springdale and started working, at first lying on job applications to say she was older.

She worked as a cashier at McDonald’s and Chick-fil-A, then in retail at Macy’s and Ross. Finishing high school was not a priority, but any higher-paying job required a diploma, she said. She thought she should take the GED.

“I thought all you have to do is take a test, then you can go off and do what you want,” said Jackson, now 19. But she was torn. “I thought people will think you are a failure, that you took the easy way out.”

Many teens leave school thinking the GED will be an easier route and are surprised at how hard the test is, several counselors and GED teachers said.

The passing score for the GED is set so that dropouts must outperform about 40 percent of graduating seniors.

For students who have struggled academically or missed a lot of school, that’s a high bar. In some ways, it’s harder than graduating, said Warees Majeed, director of workforce development at Living Classrooms, which offers GED preparation in the District for teenagers released from juvenile detention.

Researchers such as Heckman maintain that there is great value in school attendance.

If cognitive skills were enough, people who demonstrate high school equivalence by passing the GED would perform equally well in the workplace or in college, he said. Instead, dropping out of high school usually portends a lifelong pattern of dropping out, he said. Studies shows high school dropouts have higher rates of job turnover, college attrition, turnover in the military and even divorce, compared with those who stuck it out in high school.

“Sitting in school and showing up on time and doing in school what people ask you to do — those are useful, if dull, tedious traits to have,” Heckman said.

Some programs offer more comprehensive GED preparation than the average crash course that keeps participants in school-like settings longer and provide more targeted training.

In Virginia and about 10 other states, GED preparation is offered within high schools. Requirements vary, but in Virginia, students who enroll have to create an alternative education plan that includes career counseling, GED preparation courses and vocational training.

Advocates say that the program has helped students who would otherwise have fallen through the cracks. But education officials in Alexandria last year decided to stop offering the high school GED program.

Madye Henson, deputy superintendent, said the school system did not want to support a “program that is encouraging dropping out of school.”

Now the city is offering more flexible ways to pursue a diploma, including a satellite high school campus that opened in the fall at Landmark Mall. Students can go there part-time, plug in laptops and complete the high school curriculum online while still getting personal attention from teachers and counselors.

Jackson stumbled upon the satellite campus in the fall when she went to the mall to interview for a job. By then she was 18 and living on her own in Alexandria.

She abandoned her plans to take the GED and instead enrolled in T.C. Williams High School.

Eight months later, she is already taking some 11th-grade classes and thinking about college. She is still surprised she’s in high school. “I needed so many credits. I felt like it was too late,” Jackson said.