Jay P. Greene's Blog

Yesterday I chronicled the unreasonable (and unfortunately predictable)  reaction of the teachers union to my WSJ op-ed suggesting that there were trade-offs between hiring more teachers and quality teachers.  I also received a number of reasonable, but still mistaken, responses attempting to explain the 50% increase in the teaching workforce without improved results by blaming special education and English Language Learners (ELL).  A letter in yesterday’s WSJ succinctly stated the argument:

In 1970 many disabled and mentally handicapped students were denied access to public education. Today these students are guaranteed a public education until the age of 22. Also in 1970, about 5% of the U.S. population was foreign born, compared with about 20% today. Many of these children enter the education system with limited English skills and are provided services to improve their mastery of English. Such services were unheard of in many parts of the country even 20 years ago.

It is obvious from these statistics that many more special-education teachers and English-language specialists are counted in the teaching profession now as compared to 1970. Mr. Greene claims that math and reading scores of 17-year-olds are unchanged since 1970. I would submit that the teaching resources devoted to students, excluding teachers of special education and limited-English speakers, is close to unchanged since 1970.

There is a plausibility to this argument, but special education and ELL can neither account for the 50% increase in teachers nor can they be ignored when considering the stagnation in student achievement.  Special education teachers constitute about 14% of the teaching work force and disabled students constitute about 13% of the student population.  So, if we imagine, as the letter writer does, that many of these disabled students were denied access to public education, then the addition of teachers was roughly commensurate with the addition of disabled students.  Excluding all disabled students and teachers, the reduction in student-teacher ratios between 1970 and 2012 would still have been roughly from 22 to 15.  If you wanted to use as the starting point 1980, 5 years after the start of federally mandated special education, the ratio still drops from 18.6 to 15.2.

But of course not all disabled students were denied access to schools before federal legislation.  Outside of the most severely disabled, the bulk of students now classified as disabled would have been present in school in 1970; they just weren’t being served very well.  So, if we added a large number of special education teachers to better educate students who were always present but who we now consider disabled, it should have resulted in much better outcomes for those students.  But overall outcomes are flat.

There is a disturbing habit among people who make the argument represented in the WSJ letter to act as if special education is a black hole from which no progress can or should be expected.  Yes, they say, we hired more teachers, but that was for more special education students and you couldn’t expect that to result in any progress.  But this is entirely wrong.  Special education can and should result in greater academic achievement, so even teachers added in that category should be contributing to better aggregate outcomes.

All of these arguments also hold true for ELL except that ELL is much smaller and involves fewer teachers than special education.  A critic could note that the world has given the US public education system more ELL students because of higher immigration, although the same cannot really be said of special education.  Other than the exclusion of severely disabled students, whose numbers are quite small, the distribution of disabilities in the public school student population should be roughly the same today as it was back then given that most disabilities are genetic in their origin.  It’s just that we didn’t serve many of those students well in the past and therefore should expect that achievement should be rising as we devote more resources to them.  More teachers should be producing more achievement.

And yes, more ELL students might require more teachers to produce the same achievement.  But in other ways our student population has become easier to educate.  Unless students have become significantly more difficult to educate across all dimensions, it’s not possible to explain away the facts that we have 50% more teachers without any meaningful improvement in outcomes.

Several years ago Greg Forster and I addressed this in our Teachability Index, in which we tracked 16 indicators of the advantages or disadvantaged that students bring to school and found that overall students are somewhat less challenging to educate now than they used to be.  And for a forthcoming book I have updated and improved upon that analysis and still find that students are somewhat easier to educate, so it should not require many more teachers to get the same results.

We can’t blame special ed and ELL to account for the lack of productivity in education as we’ve hired more teachers.  The problem is that we’ve ignored the trade-offs between teacher quantity and teacher quality.