When do we observe a gender gap in competition entry? A meta-analysis of the experimental literature

This paper systematizes the experimental evidence on gender differences in competition preferences with a meta-analysis of 110 studies and 409 effect sizes on observed or residual gender gaps in experimental tournament entry. Our meta-summary confirms that, across all studies, men choose a tournament scheme 13 percentage points more often than women, which is only about a third of the gap found in Niederle and Vesterlund's (2007) seminal paper. Our meta-regression analysis reveals that larger gender differences are indeed prevalent in studies that most closely apply the Niederle-Vesterlund design, i.e., differences are largest in lab experiments with student subject pools and when math tasks are involved, but almost negligible for other age groups, verbal tasks, and in field-like environments. Experimental interventions such as information treatments or affirmative action measures prove very effective in reducing or even eliminating the gender gap. Although some measures of risk preferences and confidence are systematically related to the estimated residual gender gap in tournament entry, they do not eradicate competitiveness as a distinct trait. Finally, higher gender equality at the country level seems to go along with larger differences in women's and men's competition preferences.