The Effect of No Child Left Behind on the Percentage of Students Enrolled in Special Education Classes

I thought I'd use this post to discuss my other major research project that I have worked on throughout my college career. I also wrote this paper in my Junior year during my two semesters of econometrics. First off, it's probably good to go through a quick run down of what econometrics is. In a previous post, I said that I often refer to economics as a type of applied sociology. In a similar vein, I often describe econometrics as applied statistics. Just like any other scientists, economists attempt to answer questions using the Scientific Method. We form a hypothesis, test that hypothesis, draw conclusions, make adjustments, and repeat. Unlike most other sciences, however, it is often hard to develop controlled experiments to test economic theories. (Most people don't like it when you mess around with prices and incentives in the free market just to do some research). There is a branch of economics--experimental economics--that does just this in controlled settings, but this is a relatively small portion of the field. To get around these obstacles, economists use methods of statistics to control for observations and isolate variables in order to obtain ceteris paribus (all else equal) results. I'm actually taking a statistics class right now as part of my applied economics Masters program.

Anyway, about the research. The No Child Left Behind Act of 2001 (NCLB) was signed into law by President George W. Bush on January 8th, 2002. The purpose of this Act is "to close the achievement gap with accountability, flexibility, and choice, so that no child is left behind" (107th Congress, 2002). Part of NCLB was designed specifically with disabled students in mind. This legislation requires schools to administer state-wide standardized tests to their students in order to determine a "grade" for the school itself--to determine if each school has been accountable to its students. Each state is allowed to create its own tests, but each school must demonstrate "Adequate Yearly Progress" (AYP), else face decreased funding,  school restructuring, or mandatory school choice (I actually like the idea of school choice, but that's for another post).

The fundamental assumption of this legislation is that NCLB will force schools to increase teacher quality and accountability to students in order to achieve AYP, thereby decreasing the gap between low- and high-achieving students. As with most legislation, however, this Act creates incentives which may lead to some unintended consequences. For example, the calculus of school administrators will likely be changed by this legislation. Because schools, instead of students, bear more directly the cost of poor student achievement, school administrators are incentivized to "game the system" by placing marginally-performing students into special education classes. Although all students (including special education students) are required to take the state assessments, NCLB allows for accommodations--such as increased time--for students placed in these classes. By placing marginally performing students who would otherwise not be considered candidates for special education into these classes, the school is able to reduce the negative impact that these students will have on average regular-education scores, and perhaps boost the average scores of special education students.

Let's think of exactly why this might be. Consider a very simple example: a school with 10 students (Named A, B, C, D, E, F, G, H, I, and J...creative, huh?) taking a test, scored on a scale of 0 to 100. Further, let's say that the school is broken up into two classes: "Regular", consisting of A, B, C, D, E, F, and G; and "Special", consisting of H, I, and J. Let's say that the scores are as follows:

A: 100
B: 95
C: 90
D: 95
E: 65
F: 60
G: 55
H: 15
I: 20
J: 10

The average score of the "Regular" class is \[\frac{100+95+90+95+65+60+55}{7}=80\] The average score of the "Special" class is \[\frac{15+20+10}{3}=15\] If we just switch E, F, and G (who we might call "marginally performing students") over to the "Special" class and do nothing else, watch what happens. The new average score of the "Regular" class is \[\frac{100+95+90+95}{4}=95\] and the new average score of the "Special" class is \[\frac{65+60+55+15+20+10}{6}=37.5\] Just by regrouping the students (and without improving the quality of the teachers one bit) we have artificially raised the score of the "Regular" class by 15 points, and the score of the "Special" class by 22.5 points. Crazy, huh? Of course the overall average of the school will remain the same, but these classes would be reported separately with NCLB.

So we know that school administrators have the incentive to regroup students in these ways in order to artificially raise scores, but do they actually act on these incentives? This is where the econometrics comes in. I use a couple of different econometric models in my paper to try to answer this question. We don't have to go into the specifics of the models, but we should talk about their basic structure, and the data. My data range from 1996 to 2006, and include 20,624 school districts and all fifty states plus DC. Basically, the data can be broken up into two major time periods: preNCLB (1996 to 2000) and postNCLB (2001 to 2006). The dependent variable in all my models is %IEP, or the percentage of students (in a given school district or state) with Individualized Education Programs (IEPs) which are groups assigned to students in special education classes. My independent variables have to do with the time that an observation is taken. So the basic structure of all my models asks the question, "in a given year and in a given school district/state, what is the percentage of students in special ed?" We can track over time how this percentage changes, and discuss if it is reasonable to believe that any of that change can be attributed to NCLB.

If it is true that school administrators have acted on the incentives described above, we would expect there to be a sharp increase in the percentage of students in special education classes between the preNCLB period and the postNCLB period (around 2001). It turns out that some of my data show just that. If we regress %IEP on the individual years in my dataset, we can show how the percentage students in special education classes changes over time (with respect to my "base year" 1996). Below is a graph created from one of my regressions:

Now of course, this is not proof that school administrators are "gaming the system", but this is strong visual evidence in support of the hypothesis of my paper. Just as we move from the preNCLB period to the postNCLB period, there is a huge spike in the percentage of students enrolled in special education classes. There are a couple of other more technical tests that I run that provide me with even more evidence, but that is beyond the scope of this blog.

No Child Left Behind was designed to increase the math, reading, and writing skills of students throughout the United States, giving them greater preparation for life. The legislation is full of nothing but good intentions, but unfortunately also puts in place some perverse incentives that may have ended up hurting some students more than helping them. The legislation encourages school administrators to consider students more as "numbers" or "test scores"--assets or liabilities--than before the Act. This encourages them to decrease the "costs" imposed by these liabilities by regrouping marginally-performing students into special education classes, even though they would otherwise not have been considered in need of special education. This can hurt these marginally-performing students because they will not be in a setting appropriate to their needs, and it can also hurt students that should be in these special education classes, because some resources will be re-directed away from them, and towards these marginally-performing students.

Anyway, I hope this gave you something to think about. If you would like to see the full paper, shoot me an email at connor.cosenza@gmail.com

Have a magical day!

107^th Congress. (2002). No Child Left Behind Act of 2001. (PUBLIC LAW 107-110-JAN. 8, 2002). Washington, DC: U.S. Government Printing Office. <http://opi.mt.gov/PDF/FEDPrgms/USDOE/pl107110.pdf>.