Some statistical details were noted:
The Solaris Book of New Science Fiction by Boys volume one has Mary A Turzillo as token feminine contributor. One woman from eighteen listed authors. Volume Two is obviously the feminist volume with a remarkable three women out of fourteen involved. Neal Asher gets two stories though, to restore the balance. It’s back to normal for Volume Three as fifteen stories allow room for just one woman.
And finally (?) Ian Whates weighs in with anecdata!
Also posted at Dreamwidth, where there are comment(s); comment here or there.