Tuesday, October 02, 2012
Hanushek and the economics of teacher quality
I recently finished reading The 4% Solution, a policy book released by the George W. Bush Institute. The chapters, including five by various Nobel laureates, look at what sparks economic growth, and what exactly it would take to make US GDP grow by 4 percent per year. While people who don't share the former president's politics will find plenty to argue with in some of the essays, others are much more neutral politically, and focus on numbers. Eric A. Hanushek's essay on "Education Quality and Economic Growth" fits in this camp. Hanushek studies the economics of education, and has done several studies into teacher quality. What teacher attributes affect student outcomes? In this essay he makes the case that increases in cognitive skills contribute to economic growth; basically, as people learn more and become better problem solvers, they use this knowledge and these skills to create efficiencies and new products and start businesses and so forth. He argues you can put specific dollar amounts on changes in US test scores on international assessments (particularly the PISA). If US achievement levels on the PISA rose by 25 points -- putting us at the level of Germany -- this would have a present value of $44 trillion for the United States over 80 years. Putting this in perspective, the entire US economy is currently $16 trillion. Getting up to the level of Finland -- one of the top countries -- would be worth $100 trillion over 80 years. Hanushek then looks at the impact of teacher efficacy on student outcomes. His studies try to measure the "value added" contribution of teachers, looking at how different teachers instructing similar populations have wildly varying outcomes. He claims that replacing the least effective 5-8 percent of teachers with average teachers could bring the US up to a level of student achievement equivalent to that of Canada. Replacing the bottom 7-12 percent of teachers would eventually bring the US up to the level of Finland -- which was worth $100 trillion over 80 years. As he puts it, "the rewards for improvement are enormous. The economic benefits of reforming America's public schools far exceed the potential gains of a short-term focus on flattening out business cycles and from recovering from recession." It's a fascinating concept, and if true, suggests a fairly stunning amount of economic growth almost there for the taking. But, of course, improving educational quality has been a long and not particularly successful battle. He notes that "The appropriate policies to achieve these changes in teacher quality are beyond this discussion." But hopefully some people will ponder that question, and come up with solutions that could put that $100 trillion in reach.