The Tribune described the recent visit of Geoffrey Canada, the star of the documentary “Waiting for Superman” and the founder of the Harlem Children’s Zone, the “HCZ”, a monumental accomplishment in urban America. He outlined both the objectives and achievements of the HCZ; and, understandably, this did not include all the insights included in the film.
A less-prominent “Star” of the film is Dr. Eric A Hanushek, a well-known economist, who delivered the one-liner –
“Substantial economic gains can be realized by identifying the most ineffective teachers and moving them out of the classroom”.
The detailed research supporting this proposal is contained in “The Economic Value of Higher Teacher Quality”, a Working Paper of the National Bureau of Economic Research. It merits a closer look.
Knowns and Unknowns
In it Eric Hanushek notes that although an incredible amount of research has been done on learning, much has been false or misleading. He contends that teachers are important; and, in fact, no other element in the education equation rivals it in importance.
But…teachers vary greatly in their ability to impart knowledge and skills to students. “The magnitude of differences is truly large, with some teachers producing one and a half years of gain in achievement in an academic year while others with equivalent students produce only a one-half year gain.” Briefly stated…with the same students some teachers are three times more productive.
However, at this point in time he contends that we don’t know what type of person will be a highly productive teacher in the classroom. Even after hundreds of studies, social scientists like Hanushek have not identified a statistically valid causal relationship between “specific teacher characteristics” and the likely gains teachers will “produce” in student achievement.
- Class size reduction does not affect student achievement except for the very earliest grades, “and then the expected results are small”.
- Masters degrees “bear no consistent relationship with student achievement” as does experience in the classroom after the first few years on the job.
- “Conventional teacher certification requirements, source of teaching, or salary level are not systematically related to the amount of learning that goes on in the classroom.”
- “Even very intensive professional development to help teachers become more effective after they are already in the classroom has shown little impact on student achievement.”
The above policies are the ones traditionally employed.
The social scientist in this case concentrates on what he knows…namely, that poor teachers can inflict a near permanent learning impairment on their students and this impairment will persist throughout their lifetime. This adversely affects their likely earnings, their economic contribution to the nation and the welfare of the nation itself.
The author then did a “what if” exercise, a bit of “economic modeling”. He started with –
- What is known about the relationship between cognitive skills and earnings; and then asked;
- “What if a series of outstanding teachers had a class of students through the primary and secondary school years?”…and…”What would be the aggregate lifetime earnings of this lucky group relative to a similar class that had uniformly poor teachers?
- The difference is enormous…approximately $1.4 million in today’s dollars for a class of 30 students (approximately $467,000 of extra income per student) and significantly less for much smaller classes. Hanushek contends that these future economic gains should be considered as the economic value of quality teachers.
Many will be skeptical of the Doctor’s statistical correlations and prefer anecdotal evidence, “gut feel” and traditional solutions. However, this at best provides a false comfort to a country like the Bahamas in today’s global economy.
In his NBER Working Paper Eric Hanushek further states that –
- The more effective teachers should be assigned larger classes and the less effective smaller ones.
- If teacher salaries reflected teacher effectiveness more closely, then much higher salaries would be economically justified.
- “Without that linkage, we should expect our schools to underperform, and we might also expect teacher salaries to lag those in the general labor market.”
The Bahamas Department of Education (the “DOE”) is not starting from scratch. It does have good teachers; and it has a student testing and evaluation system with decades of experience.
The DOE must put that the data system on steroids. Changes have to be made so that it will track student achievement year by year and appropriately relate student performance to specific teachers. Then the results must have consequences for both.
The DOE should adopt the good Doctor’s advice.