From the book’s website:
Even though men and women have graduated law school at nearly the same rate for two decades, women still make up only 17% of partners at law firms.
Since 1995, Presumed Equal has provided valuable insight into the evolving role of women at top law firms. Based on anonymous survey responses from nearly 4,000 female associates and partners at 105 of the nation’s most prestigious firms, this 2006 edition continues to provide candid, first-hand observations on issues such as work-life balance, advancement, mentoring, business development, part-time opportunities, gender discrimination and firm leadership on a firm-specific basis.
There are few resources that can boast such a wealth of information to guide those seeking to learn more about a specific firm’s culture and to distinguish between similar firms. Presumed Equal fills this academic and professional void by providing detailed reports on 150 offices of 105 firms. While especially helpful to women seeking opportunities in law firms, this guide also reflects each firm’s attitude toward every attorney’s need to balance career advancement and non-firm interests. Furthermore, the reference manual provides insight into a firm’s responsiveness to other critical issues such as overall minority advancement and the availability of mentoring. Presumed Equal allows employment candidates to learn the questions to ask and the issues to consider when entering any conversation about what firm is right for them.
The book’s introduction (which includes the methodology) and a list of profiled firms by rank is accessible here.