All of the educational techniques that have ever been tried have one thing in common. They don’t work if the students don’t show up.

Michigan is learning this firsthand.  It has the nation’s sixth-worst rate of chronic absenteeism: Fifteen percent of Michigan students miss 1 in 10 school days. The state’s policymakers have responded by tying consequences for schools to their attendance rates.

However, a new study suggests that the most important solutions start with the family. Using new data on student homelessness, researchers at Poverty Solutions, a project at the University of Michigan, found that housing instability is by far the largest predictor of chronic absenteeism.

“If we want to actually improve attendance, we need to think about how poverty and homelessness are contributing to kids’ being absent,” said Jennifer Erb-Downward, a research fellow at Poverty Solutions who co-authored the study.

Other factors like race and poverty also predict whether a student will show up regularly for school, but housing insecurity has the largest effect by far, according to the study.

Consider the Detroit city district, the Michigan district that has been hit hardest by declining school attendance. Its rate of chronic absenteeism for all students is 56 percent — already a staggering number of missed school days.

The rate for homeless students? Eighty-six percent.

If this seems unsurprising, consider what the authors mean by “homeless.” Under federal law, the definition of a homeless student can go beyond kids who sleep in shelters or outdoors if their living situation is inadequate. That means homeless students can also live in motels or trailer parks, or “doubled up” with relatives or friends because their families can’t independently afford housing.

As a result, the study counts more students as homeless than one might expect. What’s more, Erb-Downward said the reported number of homeless students in Detroit and elsewhere is unrealistically low.

Even though the research focuses on housing issues, the study’s  policy recommendations make clear that schools can improve attendance

One suggestion is that districts should opt in to the statewide data system that alerts educators when a student’s absences begin to pile up. Fewer than two-thirds of districts statewide have signed up so far, Erb-Downward said.

Click here to see a map of Michigan school districts listed by their rate of chronic absenteeism. Scroll down to read the full study.