She sent in young volunteers, "field agents", to get some real-life insights. What she found seems like a glimpse into the obvious.
"Bright, talented teachers who are well trained and love their jobs."
Ripley says rather than "trying to reverse engineer a high-performance teaching culture through dazzlingly complex performance evaluations and value-added data analysis", as Americans do, the Finns put the focus on high-quality teaching.
Only top students are allowed to enrol in teacher training programmes, and the training for teachers is much more demanding than it is in America.
It was a similar story in Poland, which got to the upper echelons of international test-score rankings in record time by following the Finnish and South Korean formula: well-trained teachers, a rigorous curriculum and a challenging exam required of all graduating seniors.
But there were other variables too. For American high school students, sports are part of the "core culture" but at the school Ripley studied in Wroclaw, Poland, "sports simply did not figure into the school day; why would they? Plenty of kids played pickup soccer or basketball games on their own after school, but there was no confusion about what school was for."
So what can New Zealand parents take out of Ripley's valuable work? I was intrigued that the top-performing Finnish schools were described as "dingy", with desks in rows and an old-fashioned chalkboard - not an iPad or interactive whiteboard in sight.
This does seem to suggest we should be focusing first on the basics - training top teachers and giving them higher status in our society - rather than technology or infrastructure.
Perhaps we should also challenge our assumption that high performance in sports at school is linked to top academic performance.
Most importantly, we could change how we all think about teachers. I'm not talking about policy changes from the Beehive.
I mean the way ordinary people talk about teachers at dinner parties and outside the school gate. Until now the whole conversation around teachers has been dominated by the rhetoric of unions and politicians.
Among parents the attitude to New Zealand teachers tends to be grudging admiration, verging on condescension, along the lines of "I don't know how they do it".
I have said these same things myself, especially after helping out in my children's classroom.
"Wow, teachers deserve a medal for putting up with kids all day (whether little ones, or hormonal adolescents)."
I thought I was being supportive saying this, but now I'm not so sure. The subtext is: "you must be a bit bonkers, a kind of selfless loon, to choose to do this terribly hard and financially not very rewarding job".
This is not respect for a profession which is only going to become more and more crucial.
As Ripley says, everywhere she went she saw reminders the world had changed and schooling matters more than ever before.
Even for a job in a factory kids need to be able to read, solve problems and communicate what happened on their shift.
As the world changes and whole industries come toppling down, education is the variable that matters most to our future prosperity.
Perhaps it's time for us to show our teachers we know that. And guess what? We don't need to wait for politicians to do it first.
