Women have always been underrepresented in Economics. For example, regarding US faculty, the Committee on the Status of Women in the Economics Profession (CSWEP), a subcommittee of the American Economic Association, determines in its latest annual report that women represent 28% of assistant professors, 21% of associate professors and 8% of full professors in PhD granting Economics department. As a whole, they represent 19% of all Economics faculty.
The point of this post is not to complain about the low proportion of women in the profession, or about their dwindling share up the ladder, but about the lack of involvement on women in RePEc. Currently, their share is at 14.5%. It is clearly below the 19% mentioned, although it is slowly increasing (it was 13.6% a year ago and 12.7% two years ago). Why this underrepresentation?
It is of course possible that their a bias in those numbers, because the CSWEP numbers pertain only to the United States and the RePEc Author Service covers the whole world. So, let us analyze the top 1000 economists from Tom Coupé’s list. Of the men, only 22.9% are not registered taking the ranking by publications, and 32.4% with the ranking by citations (which includes quite a few non-economists). For women, the numbers are 37.2% and 44.4%. We see that top female economists are less likely to be signed up with RePEc.
Therefore, encourage women to register at the RePEc Author Service!
PS: You may wonder how these numbers are determined, as gender is not indicated when registering with the RePEc Author Service. It is inferred from first names, using a database of gender likelihood by name. For the more uncertain cases, an exception table was created using additional information, in particular from pictures on personal web pages.
The RePEc Blog 
A study at Northwestern University shows that men are more likely to share their work online than woman. Maybe they participate more in online professional networks for the same reason.