Last week, the OECD published Education at a Glance 2013, comparing education indicators across 42 countries. Ministers Steven Joyce and Hekia Parata highlighted a few points of interest. Strangely, these highlights concentrated on New Zealand’s spending on education, as if spending was a marker of success.

The Ministers pointed out that New Zealand spends 20% of its public expenditure on education, the second highest percentage in the OECD. What they didn’t point out was which country was placed 1st. It is Mexico, with 20.6% of public expenditure on education. We are 2nd in the OECD … next to Mexico!

Surely then, New Zealand and Mexico must be among the highest performing countries in the world. The Programme for International Student Achievement (PISA) study shows that yes, New Zealand is doing well in education by global standards. Our 15-year-olds are 7th in the world in reading, 13th in maths, and 7th in science. Mexico on the other hand places 50th in reading, 53rd in maths, and 55th in science.

The PISA study is often used to rank countries in this way, but it is also a rich data source for thinking about how to improve education systems. And one of the strongest stories that has emerged from PISA so far is that spending has very little bearing on performance.

In a TED talk, OECD’s Andreas Schleicher provides an elegant illustration on the relationship between education spending and students’ abilities. Success is defined by the average reading ability of 15-year-olds, and importantly, the disparity of reading ability between rich and poor. Our graph of the week shows spending has little bearing on success. “Spending per student explains less than 20% of the variation among countries,” Mr Schleicher says in his talk.

It’s not how much that is spent that matters; it’s how the money is spent. Perhaps next week when he arrives in New Zealand, Mr Schleicher will remind our ministers that pouring money into education is not something to be proud of.

Money doesn’t necessarily build better schools.