We document wide and persistent variation in women's representation and success across graduate programs in economics. Using new data on early career outcomes for recent graduates, including first job placement, publications and promotion, we compare (anonymized) departments on outcomes for women relative to men graduating from the same program. We then conduct interviews with faculty and former students from five programs higher and lower relative outcomes. We find that departments with higher outcomes for women also hire more women faculty, facilitate advisor-student contact, provide collegial research seminars, and are notable for senior faculty with awareness of gender issues. We offer our qualitative evidence as the first step in learning about "what works" in expanding women's representation in economics.