Are rigorous, college-level classes the way to raise achievement for low-income high school students? The evidence is mixed.

Recently, the International Baccalaureate foundation sent out an email proclaiming ‘yes.’ It boasted that low-income and minority students who take its courses graduate from high school and go to college at the same high rates as students from higher-income families.

The IB Diploma is a rigorous two-year course of studies, typically taken by top high-achieving students during their junior and senior years of high school. The math is calculus. The writing requires sophisticated analysis. Succeeding in this program gives students entree to the most selective colleges in the country. It’s a no brainer that kids who can accomplish that will do well and continue in school.

But when I talked with John W. Young, the organization’s head of research, about the success of lower-income students, I was surprised to learn that it’s not only those who can do the entire IB curriculum and pass all the exams who are going to college in droves. Even students who only take one IB class and sit for one exam are still closing the gap.

“The best treatment is do to the whole diploma and take all the exams,” Young said. “That’s the gold standard. But it turns out, if you can’t do that, and you just participate in one course, that’s sufficient to boost long-term educational outcomes.”

Young not only found elevated high school graduation and college-going rates, but also that low-income students persisted in college through at least the first year at the same rate as their wealthier peers. Future studies will continue to track these students.

But before anyone starts recommending that all schools should adopt some sort of IB curriculum, here’s the rub: only a third of low-income students at IB schools even make it to the lower threshold of taking one IB class. A majority of low-income students at IB schools aren’t taking any.

That’s because within IB schools, teachers and administrators decide who gets to pursue the IB Diploma or even take an IB course. Sometimes it’s based on grades or tests. Other times it’s a subjective decision. It’s unclear how students who weren’t tapped for IB are faring in regular classes in these same schools. Another big body of research shows that students who aren’t tracked into honors or advanced classes often become demoralized and their achievement suffers.

Nonetheless, more public schools are offering IB programs. The most recent data show that more than 700 public high schools (of about 26,000 in the U.S.) offer the “IB Diploma Programme,” and more than half of those, or roughly 400, are so-called Title I schools, where at least half the student population is poor enough to qualify for free or reduced-price lunch. Back in 2009, 45 percent of public IB schools were low-income.

“Historically, IB programs have been for more selective schools. But that hasn’t been the case for a long time,” said Young. “One of our mission is to make IB accessible to high-achieving students at all income levels.”

This year, there were 20 new applications to become IB schools in Chicago alone, Young said.

IB is still tiny compared with the better-known Advanced Placement (AP) courses run by the College Board. That organization has also made a push to give low-income minorities more access to its demanding classes. The organization also finds better college grades and graduation rates for students who can score a 3 or higher (see here). And over the past 10 years that number has grown greatly. In 2015, almost a quarter of a million low-income high school students, as measured by those who requested a fee waiver, scored a 3 or higher on at least one AP exam, four times as many as in 2005, according to the College Board. Nat Malkin of the American Enterprise Institute called it the “century’s biggest education success story” earlier this year.

On the flip side, a 2013 Baltimore Sun analysis found that too many students were pushed into AP classes where they foundered and failed. For school administrators, it’s a tough challenge to nurture high achievers without alienating and demoralizing the majority of their students.

Young readily admits that IB schools need to figure out how to get more low-income students into their rigorous classes. In some cases, the students aren’t academically prepared. And there’s little a school can do, realistically, to bring a student who’s reading at a fourth grade level in eighth grade up to snuff by junior year. But Young also thinks there are many low-income students performing at grade level or above, and those students should be encouraged to try. That will require many more specially trained teachers, ones who not only have college-caliber subject expertise but also the ability to reach low-income students who are typically passed over.

“There’s a lot of unrecognized potential out there,” Young said. “But if you have kids who show potential and are achieving at grade level or better, then yeah, let’s find out if they can do it. Sometimes they can rise to that challenge. But we won’t know if we don’t give them that opportunity.”

[Cross-posted at The Hechinger Report]

Jill Barshay

Jill Barshay is the founding editor and writer of Education By The Numbers, The Hechinger Report's blog about education data.