http://reagle.org/joseph/blog/social/wikipedia/gender-bias-in-wp-eb
Abstract: Is there a bias in the against women's representation in Wikipedia biographies? Thousands of biographical subjects, from six sources, are compared against the English-language Wikipedia and the online Encyclopædia Britannica with respect to coverage, gender representation, and article length. We conclude that Wikipedia provides better coverage and longer articles, that Wikipedia typically has more articles on women than Britannica in absolute terms, but Wikipedia articles on women are more likely to be missing than articles on men relative to Britannica. For both reference works, article length did not consistently differ by gender.