The purpose of this article is to introduce the technique and main findings of meta-analysis to the reader, who is unfamiliar with the field and has the usual objections. A meta-analysis is a quantitative survey of a literature reporting estimates of the same parameter. The funnel showing the...

The authours use information gathered from 122 studies on the effects of high school diplomas on wages in different countries worldwide to carry out a meta-analysis that shows high school diplomas have a statistically significant effect on wages of nearly 8%. This effect varies whether the...