The interesting part in PwC, EY, KPMG and Deloitte making the 2013 Working Mother 100 Best Companies is not that they all made the top 10, but this quote out of EY:
As Karyn Twaronite, partner of Ernst & Young LLP and the EY Americas Inclusiveness Officer (EY has been on the list for 17 years and this year is once again among the Top 10) told me in an interview: “We want to be the most progressive firm for working moms. We take that very seriously. We want to stay as competitive as possible to attract and retain the best talent.”
Once again, however, EY is no more or less competitive than the competition.
They do get to brag that they placed higher on the list than Moss Adams, Rothstein Kass and McGladrey so there's that but even the clients know there's no competition there.
2013 Working Mother 100 Best Companies [Working Mother]