The full "unrestricted" sample in Table 1 represents all of the students who have taken the economics EOCT in the 2005-06, 2006-07, or 2007-08 academic years and had previously taken both the geometry and algebra EOCTs.
The outcome of interest is the EOCT score in economics.
In this paper, the input of interest is taking an AP Economics course as opposed to a "regular" economics course, and the outcome of interest is student achievement in economics as measured by the state of Georgia's high-stakes EOCT.
We use PSM as a technique to isolate the impact of the AP Economics course on the economics EOCT from the factors that initially led the student to take the course.
the effect of taking AP Economics on performance on the economics EOCT for those who take an AP Economics course).
We observe the first term on the right-hand side of Equation 1, the economics EOCT scores for students who actually took AP Economics.
Once we generate the matches between treatment and control students, we then calculate the average economics EOCT score for these control students (D = 0) who have been matched to our treatment students (D = 1) and use this average as an estimate of the second term on the right hand side of Equation 1.
Because we have a strong measure of students' prior achievement in the form of EOCT scores in algebra and geometry, we believe that ITA holds.
Below, we provide evidence that controlling for unobserved school quality does not seem to impact the estimated effects of AP course taking on Economics EOCT scores--once we control for unobserved teacher quality.
To create baseline estimates and to establish the validity of our matching variables, we first estimate a linear regression (Equation 2) that models each student's standardized economics EOCT score ([EOCTScore.
t], a vector of shift parameters that captures the effect of time-invariant teacher characteristics on student economics EOCT scores:
The OLS results imply that students who choose to take an AP class in economics score much better on the economics EOCT than do students who do not take an AP class in economics.