When you break a bone, being told that an X-ray confirms the break is little relief. You already know there is a problem, but what you really want to know is how to fix it.

Last week Unicef released a study that found New Zealand has one of the most unequal education systems in the world.

The report included measures on Early Childhood Education attendance and the size of the gap in reading scores. Gaps in educational achievement were driven by parental occupation, migration background, gender, and differences between schools.

The finding will not be a surprise to anyone following education issues closely. What is surprising is that in the accompanying commentary on how to fix the problem, looking at what is happening in schools was not front and centre.

Unicef NZ executive director Vivien Maidaborn says, “[the report is] like an x-ray. It can show us what is broken, but it doesn't explain the reason it ended up that way.”

That did not stop experts and commentators quickly blaming poverty and unconscious bias as the cause of the gap. Many of the suggested policy solutions for closing the gap then focused on alleviating poverty and racism.

That is like your doctor confirming you indeed have a broken bone, but the bigger problem is that you need to quit smoking.

Let’s go back to the x-ray.

The Unicef report only focuses on one bone in the system: inequality.

Inequality in average educational achievement can obscure the real gains and improvements some students are making. There is a lot we still need to know about the health of individual schools, teachers and students. We need to know the variation between students who share the same socioeconomic backgrounds.

The New Zealand Initiative has developed a model that controls for a student’s socioeconomic background (and other factors that might contribute to education outcomes) to estimate the value a school adds to its students.

Imagine growing up poor in New Zealand and being told that until poverty is addressed and teachers are less racist, you have no hope of bettering your life or achieving the same as your peers.

Some schools can and do improve the prospects of their students, and the Initiative believes these schools deserve more credit and their practices should be better understood.

If Unicef gave us an x-ray of a bone in the education system, The New Zealand Initiative will be producing a full body MRI.