Virtually every firm claims that it is committed to helping women succeed. And they all seem to offer an array of women’s programs - affinity groups, business-development training and work/life balance initiatives.

Firms talk a good line, but how many can demonstrate that they are promoting a strong percentage of women into the equity-partner ranks?

We probed that question by compiling partnership data as part of The National Law Journal‘s NLJ 250 survey, which ranks the largest firms in the United States by headcount. Data collected from 221 firms show that women represent 15.1 percent of equity partners. Among all partners — equity and nonequity — the figure is 18.8 percent.

That’s progress since 2003, when NLJ and Daily Report affiliate The American Lawyer compiled similar data, though the pace of change has been slow and tenuous. The overall percentage of women in equity and nonequity partner positions then was 16 percent. As for equity partners, the National Association of Women Lawyers said in a 2011 report that women have been “fixed” at 15 percent of the equity slots for the past 20 years.

At just five firms surveyed, women make up more than 25 percent of equity partners. These firms are Fragomen, Del Rey, Bernsen & Loewy (42 percent female equity partners); Jackson Kelly (28.4 percent); Ice Miller (26.9 percent); Best Best & Krieger (26.7 percent); and Ford & Harrison (26.1 percent).

Regional and highly specialized firms dominate the top 20 firms with the highest percentage of female equity partners. Among the top five, for instance, New York’s Fragomen specializes in immigration; West Virginia’s Jackson Kelly in energy and mining; Indianapolis’ Ice Miller in employment law and municipal finance; California’s Best Best in public agencies; and Ford & Harrison in employment law.

Wilmer Cutler Pickering Hale and Dorr, with 23.2 percent women equity partners, is the largest firm in the top 20 and the only one that ranks in the first tier of the NLJ 250 and the Am Law 200, The American Lawyer‘s survey of the highest-grossing firms in the United States.

Is a WilmerHale a lonely anomaly among the top-earning firms? There are signs that other national and Wall Street players are gaining ground. Nine years ago, Davis Polk & Wardwell was the only Am Law 100 firm with more than 20 percent women in its equity ranks. The list now includes Davis Polk and WilmerHale, as well as Covington & Burling; Manatt, Phelps & Phillips; Paul, Weiss, Rifkind, Wharton & Garrison; Ropes & Gray; and Willkie Farr & Gallagher.

ANOTHER SIGN

Another positive sign: Women are gaining ground at firms with high profits. Of 18 firms with profits per partner exceeding $2 million, 11 have equity partnerships that include more than 15 percent women. Three in that group have more than 20 percent: Paul Weiss ($3.095 million); Willkie Farr ($2.145 million); and Davis Polk ($2.3 million).

What many of the high-profit firms share is the single-tier partnership structure. For whatever reason, women seem to fare better in one-tier firms. (According to our research, women make up 17.6 percent of the equity partners in single-tier firms, but only 14.7 percent in those with two tiers.) Women in two-tier systems tend to get pushed into the nonequity ranks, explained Elizabeth Tursi, the chair of Women in Law Empowerment Forum, a group that tracks women’s progress in the legal profession: “I think it’s no secret that women are disproportionately affected by firms with more than one tier,” Tursi said.

For the most part, the needle seems to be moving in the upward direction for women equity partners at the largest, most profitable firms — albeit slowly. Nine years ago, for instance, firms like Cravath, Swaine & Moore and Sullivan & Cromwell had female equity partner numbers in the single digits (8.9 and 9.9 percent, respectively). Today, they have almost doubled those numbers (Cravath now has 15.5 percent; Sullivan 18 percent). Less dramatic, but also notable, are gains women made at other Wall Street firms like Cahill Gordon & Reindel (from 12.4 to 19.5 percent); Simpson Thacher & Bartlett (12.2 to 19.4 percent); Paul Weiss (13.2 to 20.6 percent); and Willkie Farr (13.8 to 20.6 percent).

But not all national firms are making progress. In 2003, Milbank, Tweed, Hadley & McCloy was dead last among the most profitable firms for female equity-partner rates (6.9 percent), and today the picture is hardly better (it is now at 7.6 percent). At that time, Milbank chairman Mel Immergut said he was aware of the problem and had instituted part-time work and mentoring to improve the situation. We contacted Milbank for this article, but it did not respond to our request for an interview.

Milbank might take comfort that it is not the worst from that crop of firms we looked at back in 2003. Today, Cad­walader has that honor; its female equity partner rate is 6.6 percent. In 2003, it was at 10.3 percent. Both Milbank and Cadwalader were behind corporate powerhouse Wachtell, Lipton, Rosen & Katz. Wachtell has the highest profits per partner among Am Law 200 firms ($4.4 million), and is known for its small partnership and intense transactional practice. Since 2003, the number of women in the equity partnership has dropped dramatically — from 12.3 percent to 7.7 percent.

A QUESTION OF CULTURE

Partnership structure and practice focus have some bearing on why some firms are making progress while others seem to be lagging behind. But firms with successful track records all point to something much more ephemeral. “A lot of this is cultural, which is hard to define,” said Carol Clayton, a partner at WilmerHale. “There’s been a long-standing appreciation of the importance of women to the firm.” And that appreciation, she added, has been enhanced by the high-profile women (among others, Charlene Barshefsky and Jamie Gorelick) who have come to WilmerHale from the government over the years.

A culture of inclusion is key, partners said. “Women felt accepted here,” said Ice Miller partner Brenda Horn, who started at the firm in 1981. She noted that four women and three men started in her class, and that three of the women and two of the men stayed on to make partner. “We were always less conventional [than other firms in Indiana]. Your pedigree and who you played football with didn’t matter here.”

Partners at other firms with high female-equity partner numbers also say that their firms’ success with women go beyond formal programs and policies. “The culture drives it,” said K. Allison White, a litigation partner in Ballard Spahr’s Denver office who started her career at a big New York firm. “It’s something that can’t happen overnight; it has to be long ingrained in the culture,” added Ballard partner Lynn Rzonca.

Culture can trump formal programs when it comes to women’s success. Jackson Kelly partner Kathy Beckett, who also leads the firm’s environmental practice, said her firm has no formal women’s initiative at all beyond spontaneous get-togethers. “I’ve asked some of the other girls to join me for cocktails before a firm event,” she said. “If I tried to regiment it, people will say, ‘Have you lost your mind?’”

But she said informal mentoring goes on all the time at the firm, and that the firm is too small and busy to ignore talented young women. “I think times are changing. … I can’t imagine anyone would be so narrow-minded to bypass a woman if she’s the best lawyer for the job.”

Indeed, there’s the sense that firms with a record of success with women feel progress is inevitable. Ballard chairman Mark Stewart said that although half of the new partners have been women in recent years, he’s no longer surprised: “I don’t think it’s amazing anymore. I think that’s what’s going to happen.” The firm, he said, has evolved to a point where the sex of the associate coming up for partnership is barely noticed. “Whether someone is female or male is a nonissue.”

Vivia Chen writes for The National Law Journal, a Daily Report affiliate.

A full chart from The National Law Journal’s special, Women in the Equity Partnership: How Firms Fare, is here.