Semiparametric Decomposition of the Gender Achievement Gap : An Application for Turkey

Using the data from the 2006 Programme for International Student Assessment (PISA), this study sheds light on the gender gap in mathematics and science achievement of 15-year-olds in Turkey. We apply a semiparametric Oaxaca-Blinder (OB) decomposition to investigate the gap. This technique relaxes the parametric assumptions of the standard OB decomposition, accounts for the possible violation of the common support assumption and allows us to explore the gender test score gap not only at the mean but also across the entire distribution of test scores. Our findings provide evidence that the failure to recognize the common support problem leads to the underestimation of the part of the gap attributable to observable characteristics. We find that girls outperform boys in science while the gap is not statistically significant in math. School characteristics are the most important observable characteristics in explaining the gap. We also find that the gender test score gap changes across the distribution. ; published