Is Four Better than Three? The Effect of the 4-Year High School Policy on Academic Performance in Ghana

This paper examines the effect of increasing the length of senior high school education on immediate academic performance. We exploit a unique natural experiment that extended high school duration by one year in Ghana from 2007 to 2009. Following the policy’s reversal, the 2009 and 2010 high school cohorts experienced exogenously different years of schooling but took the same exit examination in 2013. Using administrative data on the two cohorts, we find that the extra year of high school substantially increased performance in all subjects. We find the most economically significant improvement for two core subjects with the lowest historical pass rates—Core Mathematics and Integrated Science. Analysis by gender demonstrates that the policy closed preexisting achievement gaps in favor of female students for Science, Technology, Engineering, and Mathematics (STEM) subjects. The results suggest that relaxing learning time constraints may improve academic achievement and close gender gaps in STEM fields