paycheck-driven workers, and they stay longer when they do, an average of three years before leaving. So, given their desire to stay in and their relative resilience, what ultimately pushes them out? The top reasons cited in our survey were children's needs (with 44 percent selecting this as one of their top reasons) and the cost of childcare (35 percent). But many selected other factors, including a lack of flexibility (12 percent), no part-time options (8 percent), and having to work more than 40 hours per week (7 percent). Cumulatively, these "push factors" paint a picture of employment as an either/or choice: You are committed either to your career or to your family -- not both. It becomes a no-win situation. As a result, some researchers have argued, women "opt out," and companies miss opportunities to diversify their ranks and to recruit talent with that valuable "career" mindset. Although this group represents only 10 percent of our survey respondents, the Center for Work-Life Policy estimates that 43 percent of highly qualified working mothers leave the workforce at some point in their career and stay out an average of two years. The cost isn't just in lost opportunity. According to new research commissioned by the Council on Contemporary Families, women who want to work but don't have a job run a greater risk of becoming depressed. On the flip side, a high-quality job seems to protect against depression. Even moms who didn't want to work outside the house reported lower rates