A study conducted by the Massachusetts Institute of Technology’s Workplace Center found what most of us already know: Women are less likely to make partner at large firms because of difficulties faced in blending work and parenthood. MIT's Workplace Center said it surveyed 1,000 Massachusetts lawyers and found that 35% of female associates with children left large firms between 2002 and 2004, compared with 15% of male associates with children. The authors found that most male lawyers have spouses who are less career-oriented and can assume childcare responsibility, while female lawyers tend to have spouses with an equal or greater commitment to career and who earn as much or more. In a nutshell: long work hours and parenthood don't mix. The full study can be accessed in PDF format here.
Data for the number of female lawyers at NLJ 250 and AmLaw 200 firms is available through ALM Research Online in the current (2007) Diversity Scorecard spreadsheet, available free to subscribers and for $250 for non-subscribers. Diversity Scorecard also includes the data and rankings from this year’s report on minority lawyers at NLJ 250 and AmLaw firms. Historical data is also available to premium subscribers for the years 1984, 1985, 1990, 1992, 1996, 1998, and 2001-2006.