The low ROI of focusing narrowly on teacher quality

Eric A. Hanushek, Marc Piopiunik, and Simon Wiederhold just published a study on international teacher quality.

They looked at an international sample of teacher cognitive ability (as measured by OECD’s Program for the International Assessment of Adult Competencies) and student achievement (as measured by PISA scores).

They found a lot of variation of teacher cognitive quality across countries.

Teachers in Finland and Japan score very well. Teachers in Italy, Russia, and Israel score poorly.

After running regressions and controls, the authors estimate that a one standard deviation increase in teacher quality leads to a .15 standard deviation in student achievement.

To put a one standard deviation increase in context, a one standard deviation bump from the mean in IQ scores is about 15 points.

I can’t think of a realistic intervention that, at scale, will lead to that kind of increase in teacher cognitive ability across the entire United States.

For me, this is just one more study that validates the idea that institutional change is the best hope we have for increasing educational opportunity.

High-performing urban charter school sectors across the United States often achieve a ~.1 standard deviation effect over the course of three to four years.

I believe we can thoughtfully grow these non-profit public schools in a manner that maintains quality at scale. I also think we can empower amazing district leaders by letting them adopt non-profit governance for their schools.

I really can’t think of a way that we increase teacher cognitive ability by one standard deviation at scale.

In every city we work in, we do invest in recruiting and supporting great teachers. Teachers should be recruited hard, paid more, and supported better.

But I’m skeptical that focusing most of our energy on improving our teacher pool is the best way to help low-income kids.

Instead, I think we should focus much of our energy on creating and expanding great public institutions where teachers can work.

Another way to say it: I don’t blame our teachers for the dysfunction that plagues many schools in cities across the United States.

It’s their employers that should be the focus of our attention.




5 thoughts on “The low ROI of focusing narrowly on teacher quality

  1. Leighton

    This is fascinating. I wonder if the study’s cognitive skills data includes measurements of conscientiousness? Conscientiousness seems harder to measure than literacy and numeracy skills, albeit I am no psychology expert. I am just assuming. Intellectual processing power is valuable but seems to lose value if that power is not structured into foundational work ethics of patience, efficiency, temperament, and effectiveness. If I was a school hiring administrator, I would focus on identifying conscientious traits before intellectual prowess. Perhaps they are interdependent?

    1. nkingsl Post author

      Great to hear from you. Agree that IQ has diminishing returns and conscientiousness probably very valuable. Not sure on how correlated they are….

  2. John

    I think this is axiomatic in any system – the team with the best talent does not consistently win. Creating a culture that enables any talent to excel, solve problems, and outperform their potential is what separates great teams and other organizations. However, these require leaders with high EQ who are facile in adapting the culture to the needs of growth while maintaining a North Star. I do not see how any public institution (at least government-led) can be structured to do this over a long period of time. I think you need highly accountable stakeholders.

    1. nkingsl Post author

      Agree. Also, the political turnover of elected boards makes it very very hard to lead maintain a consistent vision, strategy, and culture.

  3. Mike G

    Good post.

    What do you make of the fact that some charter networks, like kipp, have a teacher recruiting strategy that hanushek might describe as high cognitive ability, whereas other charters have “typical” American teachers in that regard?

    Does it matter in terms of trying to distill the practices of high performing charters, and explaining to the founders of new charter schools?


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