KALAMAZOO, MI -- The Kalamazoo Promise "significantly" increases college college graduation rates and offers a substantial return on the dollars spent, according to the first major study of the scholarship program's post-secondary outcomes.

The biggest finding: Promise-eligible students are a third more likely to graduate college within six years of finishing high school compared to their pre-Promise peers.

The researchers also estimate The Promise yields an estimated $4.60 in benefits for every $1 invested. That means the $66 million spent so far on the program has an estimated return on investment of more than $300 million, based on the projected increase in wages over 30 years for students who wouldn't have graduated college otherwise.

The paper, "Effects of the Kalamazoo Promise Scholarship on College Enrollment, Persistence and Completion," was released today by the W.E. Upjohn Institute for Employment Research. It was co-authored by Tim Bartik, Brad Hershbein and Marta Lachowska. (Click here to read the complete study.)

"The question with The Promise has always been: Does it have a large effect? The answer is yes," Bartik said. "I was actually surprised to see how big of an effect it had, and that it was so clear-cut.

"A lot of times you get data that's muddy," he said. "This was pretty clean."

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The Promise is a universal college scholarship program for graduates of Kalamazoo Public Schools. The program is funded by anonymous donors and is marking its 10th anniversary this year.

In analyzing the outcomes to data, Hershbein said he was most surprised to see the improvement in college completion rates were just as strong for low-income and minority students as for white and middle-income students.

"Going into the project, I thought there was a distinct possibility the effects would be concentrated among relatively well-to-do students who would attend better colleges and/or accumulate less debt (which we can't measure), with a perhaps modest boost to their completion rates," Hershbein said in an email. "I did not necessarily expect that completion effects would be at least as strong among poorer students or ethnic minorities."

The findings are "incredible," said Janice Brown, the former Kalamazoo Public Schools superintendent who worked with the donors to create The Promise a decade ago.

"This is the first study that has true meaning for the community, that is answering many of the questions that people have been asking," she said. "The results are pretty powerful. It shows The Promise pays off more than any capital improvement project."

The study was funded by the Upjohn Institute with support from the William T. Grant and Lumina foundations.

The findings

Unveiled in November 2005 when Brown was superintendent and Bartik was KPS board president, The Promise started with the Class of 2006 and pays the college tuition of any KPS graduate who lives in the district and started in the district by ninth grade.

It covers all Michigan public colleges, and was just expanded to include 15 private colleges in Michigan. Students have up to 10 years after they graduate high school to use the scholarship.

So far, the program has paid $66 million in college costs for about 3,800 students.

To measure the impact of The Promise, researchers analyzed the changes over time in college enrollment, number of credits taken and post-secondary program completed for both students who qualified for The Promise and those who did not.

They found The Promise had an impact on all three areas. Compared to similar students before the Promise was created, the Promise-eligible students were:

14 percent more likely to start college the fall after high school graduation and a third more likely to enroll at a four-year university.

40 percent more likely to attend a Michigan public university or college versus an out-of-state school or private college in Michigan.

Taking more college classes. By the fourth year after high school graduation, the average Promise-eligible student had enrolled in the equivalent of two or three more classes compared to what would be expected by looking at similar students before the Promise was created, and compared to their non-eligible peers.

A third more likely to earn any post-secondary credential. Before The Promise, about 36 percent of comparable KPS graduates earned a college degree or other post-secondary credential within six years of graduating high school. Among Promise-eligible students, that increased to 48 percent, boosting the number of post-secondary graduates by a third.

A third more likely to earn a bachelor's degree. Before The Promise, 30 percent of comparable Kalamazoo graduates earned a bachelor's degree within six years of their high school graduation. That increased to 40 percent of Promise-eligible students.

The study also found the impact of The Promise seemed greater for women and minorities, although many of the differences among sub-groups were not statistically significant due to smaller sample sizes.

About 62 percent of KPS students are non-white and about 70 percent qualify for the subsidized lunch program.

Conducting the study

This study is the first analysis to compare college graduation rates for KPS students before and after The Promise, said Robert Jorth, executive director of The Promise.

"We didn't know for sure what was going on before The Promise," Jorth said. "We thought things were improving, but we didn't have any idea in terms of the scale.

"To hear the numbers, it's staggering -- in a good way."

To create the comparison, Bartik said researchers first had to wait for enough Promise-eligible students to get through the six-year window after high school graduation to collect their college graduation rates.

The researchers also had to create a database of pre-Promise students, no easy task since college graduation rates by high school are not readily available. Upjohn researchers did it by obtaining KPS graduation lists and running the names through the National Student Clearinghouse, which matches student identifiers against college records from around the country.

The study's Promise graduation rates are based on the Classes of 2006, 2007 and 2008. Based on those findings, Bartik and Hershbein say they can make some projections about the 4,400 Promise-eligible students who graduated from KPS between 2006 and 2014.

It is reasonable to assume that about 1,308 would have obtained bachelor's degrees within six years of high school graduation and another 268 would have earned an associate's degree or other post-secondary certification regardless of whether The Promise existed, Bartik and Hershbein say.

As a result of The Promise, they estimate an additional 427 students will get a bachelor's degree and another 114 students will get an associate's or other post-secondary certificate.

That's an additional 541 people now likely to earn significantly higher wages than they would have with only a high school diploma.

RELATED: 6 takeaways from the Kalamazoo Promise study

There are also societal benefits, Bartik said. College graduates generally pay more taxes, have high employment rates, are less likely to use social service programs, more likely to marry and less likely to divorce, more likely to volunteer and be engaged in civic activities.

The children of college graduates also benefit. Parents of college graduates do better in school and are more likely to grow up in a stable home, which means less stress and fewer behavior issues.

In addition, greater skills help make a local economy more attractive for business investment and job creation, according to the researchers.

Just looking at the projected increase in lifetime earnings for Promise-eligible students makes The Promise a profitable investment, the researchers say.

"If you were an investor in The Promise and you could somehow collect the extra earnings generated by KPS graduates as a result of the fact more students graduated college," that return is estimated at 11.3 percent a year, compounded annually, Bartik said.

"That's huge. Better than the stock market," he said.

"That's not even counting a lot of the benefits of The Promise," such as the $66 million in tuition costs saved by KPS parents and students, Bartik said.

Bartik and his co-authors also stress they feel their numbers are conservative. It is likely, for instance, that post-secondary success rates also have improved for KPS students who don't qualify for The Promise.

"When all your peers are going to college, that has to have an effect," Jorth said.

Bartik and Jorth also say it is likely college graduation rates for Promise students will continue to improve as KPS better prepares students for college-level work.

In fact, Jorth said the grade-point average for Promise students at Kalamazoo Valley Community College has trended up in recent years, a heartening sign.

Why aren't the numbers higher?

While Bartik said The Promise has had "very, very large effects," he acknowledged some may be surprised the impact isn't bigger.

But he said the numbers compare very favorably to other efforts to improve academic outcomes.

"When you're trying to change behavior, it's very hard," Bartik said. "A lot of things don't work."

Some may also question the expenditure of $66 million on tuition when researchers acknowledge that a third of Promise-eligible students would have completed a post-secondary program regardless and another 52 percent of students fail to earn a degree or certificate within six years.

Why not concentrate resources on the 12 percent who directly benefit?

"I doubt whether it would be possible to easily predict whose behavior will and won't be affected by The Promise," Bartik said. "There would be lots of errors of misclassifying people."

The Promise's success appears linked to the fact it is simple, generous and universal, Bartik said.

"In order to change people's behavior, you have to make an offer they understand," Bartik said. "The Promise has a very simple message: Your college is paid for, and it's up to you to decide whether to take advantage of it."

A more targeted program, Bartik said, would be "at the very least, a totally different program, and probably a less effective program."

"A simple message of 'you all can go to college' becomes a message 'we think a few of you need an extra financial boost to go to college, and we are going to have you jump through multiple hoops to see who needs that boost,'" he added.

From a larger public policy standpoint, Hershbein said the study is noteworthy because previous research on college scholarship programs "overwhelmingly suggest that more money gets more people to attend college, but there's far less certainty when it comes to actually finishing."

"Things would seem to be even less certain for universal scholarships, where there's no merit requirement," he said. "There's very little, if any, prior research in the past few decades on the effects of scholarship money to all students, not just those above some academic threshold."

The Upjohn study shows a universal program can indeed increase graduation rates.

No question, some KPS students would have graduated college regardless, although The Promise may impact their choice of school, Herschbein said.

"But a good chunk of students upgrade" from community college to four-year schools, "and that may be enough for them to finish their degree," Hershbein said. "Even those who don't finish may benefit" from taking some college classes and boosting their skills.

Bartik said the study counters the argument posed by those who say that student ability and motivation, not money, is the real barrier to boosting college graduation rates.

The Promise numbers show "money alone makes a big difference," he said.

"Has every kid who is eligible (for The Promise) succeeded? No," Bartik said. "It doesn't solve all our problems. ... But for some kids, it's made their future a whole lot brighter."

Julie Mack is a reporter for Kalamazoo Gazette. Email her at jmack1@mlive.com, call her at 269-350-0277 or follow her on Twitter @kzjuliemack.