Gathering data to investigate this is tricky, you cannot really run a randomized controlled trial, so everything is always observational. This meta analysis st

Gathering data to investigate this is tricky, you cannot really run a randomized controlled trial, so everything is always observational. This meta analysis study suggests that the suggests that the effect size of having a woman in the board is negligible, but the average number of women in the boards of the considered companies was low: https://www.researchgate.net/publication/276057102_Does_Gender_Matter_Females_on_Corporate_Boards_and_Firm_Financial_Performance_-_A_Meta-Analysis https://www.researchgate.net/publication/276057102_Does_Gend... However more recent research finds a positive effect if the number of woman is higher ( they do not report an effect size though): https://jfin-swufe.springeropen.com/articles/10.1186/s40854-021-00265-x https://jfin-swufe.springeropen.com/articles/10.1186/s40854-... This invites a "Laffer curve" like argument: surly we just do not have enough female board members jet.