Philosopher Christina Hoff Sommers, now a Research Scholar at the American Enterprise Institute, asked me to share this recent video (followed by a transcript of it).  Comments are open at that site, and Dr. Sommers writes, "I will do my best to reply to questions and objections."  

As longtime readers know, I'm skeptical that the underrepresentation of women in philosophy is due to the "argumentative" nature of the subject, lack of female authors in the canon or on syllabi, and the like.  The evidence of stereotype threat based on gender is also very weak, though implicit and explicit bias is more real.  What Dr. Sommers ignores, I fear, is the role of a previously permissive culture of sexual harassment, but that, fortunately, is changing (at last).