This will only take a minute. I promise.
VIDA has published a comparison by gender of both bylines published and books reviewed by a wide range of magazines and journals. In a super accessible format, no less. Of course, the men are disproportionately represented in almost every area:
Depressing, no? Cue the rash of quasi-misogynist explanations and rationalizations for this phenomenon. Women just aren't assertive enough when pursuing publishing opportunities. Women just tend to write chick-lit, and not the real serious important stuff the public is really interested in. Etc, etc, blah, blah, blah.