Is the supply of and demand for women candidates heterogeneous for parties across the political spectrum? And if so, what are the implications for this asymmetry for the characteristics of the women candidates we observe? In this paper, I develop an economic theory of candidate selection based on the supply of and demand for female candidates across parties on the left and the right. I examine how differential levels of competition on the left and the right, coupled with informal institutions like attitudes towards gender roles, shape the qualitative characteristics of female candidates. Using data for 11431 women candidates from 61 elections in 23 Western parliamentary democracies between 2005 and 2021, I test my theoretical expectations on five candidate-level characteristics from the Comparative Candidates Survey. My large-n cross-national study shows that there are qualitative differences between women candidates of the left and women candidates of the right across all five indicators. I explore how the supply of, and demand for female candidates has normative implications for our understanding of women’s representation.