This paper takes a mixed methods approach to address the puzzle of the persistence of gender imbalance in political recruitment and elections in the case of French parity sanctions in the National Assembly Elections from 2002 to 2017. Based on a “concurrent nested strategy” (Cresswell 2003), we use a national level qualitative analysis of the candidate selection process and the implementation of parity sanctions against political parties; quantitative analyses of the socio-economic profiles of French representatives and candidates in the National Assembly in relation to their political party affiliation; and field-work in three legislatives constituencies, two in Paris and one in Burgundy on the candidate selection process for the 2017 legislative elections to identify gendered time and money constraints. The study shows the limits of parity reform, the resistance of established gendered practices in political parties at all levels and the value of using mixed methods analysis for solving the puzzle of gender imbalance in political representation and for the study of the Comparative Politics of Gender more broadly speaking.