On the size of sheepskin effects: A meta-analysis

We use information gathered from 122 studies on the effects of high school degrees on wages in different countries worldwide to carry out a meta-analysis that shows high school degrees have a statistically significant effect on wages of nearly 8%. This effect varies either when the review is made in countries away from the tropics or when factors such as sex, race, and continent are taken into account. Our results also reveal the existence of a publication bias that tends to increase the magnitude of the sheepskin effect. Nevertheless, when the former is included into the analysis the later remains statistically significant.