Five years ago, Chrystal Olson was on drugs. She was tired of dragging her children along in that lifestyle in Tacoma, Washington.

Today, Olson, 36, is in the PTA at McCarver Elementary School in Tacoma. She has a job, working as a cashier at Kmart. She completed her GED last year and will go to Tacoma Community College in the spring to finish her degree.

Olson’s family and 38 others are participating in a pilot program run by the Tacoma Housing Authority. The idea is to give housing vouchers to families with children enrolled at McCarver Elementary.

Three years in, it seems that turnover at the school and its ill effects have tapered off.

Education Secretary Arne Duncan recently pointed to the program as a way of “thinking differently” about the relationship between public housing and education.

“I never thought I would be here today,” said Olson, who lives with three of her kids. “Before I started with this program, there were so many other things for me to worry about before trying to get a job.”

McCarver Elementary has the highest amount of homelessness among parents and children in the region. It also has the highest turnover — the rate that students come and go for reasons other than a promotion to another grade level. It ranged between 100 percent and 179 percent before the program started in 2011. That means for a teacher with a class in the beginning of the school year, her students would have turned over once in the aggregate and, in some years, almost a second time.

“Any worries that [students] bring with them makes it difficult for them to concentrate in school,” said Janet Gates-Cortez, the principal at McCarver. “If they’re worried about where they’re going to stay at night, or what food they’re going to eat next, those become the basic needs that need to be met first in order for them to really learn at school.”

Student turnover is a national issue. Thirty-four percent of public school eighth-graders switched schools twice after kindergarten. Eighteen percent switched three times.

On the extreme end of the issue are students who moved four or more times before reaching high school. Those 13 percent of students are disproportionately poor and African-American, according to a 2010 Government Accountability Office report.

“Somebody made the analogy, it’s like teaching in a train station,” said Jean Brownell, manager of educational programs at the Tacoma Housing Authority. “It ’s like people are coming and going all the time and you don ’t know who ’s going to be there from one day to the next. And even if you ’re the student who stays, it ’s impossible to learn when the teacher has to keep starting over.”

Tacoma has a special designation from the Department of Housing and Urban Development, called Moving to Work, that allows the housing authority more flexibility in how it spends its housing funding.

Tacoma is one of 39 housing authorities among 3,400 across the U.S. that have this flexibility with federal funds. That latitude makes the McCarver program and others like it possible, according to Michael Mirra, the executive director of the Tacoma Housing Authority.

This means that there could be barriers for other housing authorities — lacking the Moving to Work designation — to replicate the McCarver pilot.

It works like this. In year one of the program, families pay $25 per month in rent. By the fifth year, they are expected to pay almost the entire monthly sum for their housing. The parents must keep their kids at McCarver and they must commit to participating actively in their schooling. In addition, the housing authority has two full-time caseworkers who have offices at the school.

The main cost of the program is indeed the housing dollars, but the view of housing officials is that they would be spending those dollars anyway. The real cost is the case workers.

“Parents are there for pick-up and drop-off anyway, so they can drop by the office,” Brownell said in a telephone interview. “There ’s also a lot more ability to have teamwork when they ’re there, so if some student is having behavioral issues that day, the caseworker is right there.”

The school’s annual turnover rate declined from 107 percent prior to the initiative, down to 96 percent after the first year, and down to 74 percent after the third year. The turnover rate of the families in the program is under 10 percent. Reading scores of their children have improved, compared to their peers.

Families have also experienced increases in employment, education and job training. The mean earned income of the families has more than doubled since their entry into the program.

“The challenge is how to spend a housing dollar, not just to house a needy family, but to get these educational outcomes,” said Mirra, the executive director. “When it works, it becomes a very good use of a housing dollar.”

So the program has shown results. But there are still some issues to work through.

A third of the families have not prospered because of disability and trauma, according to Mirra. He said that the housing authority will have to modify its design to better account for that group, which includes people with mental health issues.

“We should have been focusing on getting them the correct benefits that they should have been pursuing,” Brownell said. “Many probably should have been on disability.”

Another development in the fourth year of the program — when families are expected to pay 60 percent of their rent — is that some are struggling to make the higher payments. In retrospect, Brownell said it didn ’t make sense not to tie the rent payments to income.

The housing authority is now in a position to determine if this program is effective and whether it should be extended to other schools in Tacoma.

Chrystal Olson is just happy that she was a part of the pilot program.

“Now, I want to pay back the debt that I have,” she said. “That’s my goal. … I wish we could get this for other schools.”