Using the GEPP template (Engeli, Mazur, 2018), we propose to analyze the implementation of Equal Pay policy in France since the coercive law imposing a collective bargaining in 2001, completed by the introduction of a timetable and targets of results in 2006 and financial penalties in 2012 for non-compliance. This research combines a quantitative analysis of 184 equality agreements and actions plans elaborated in 2014-2015, with qualitative fieldwork (20 case studies). We will develop our results through three analytical dimensions: the apparent positive outputs of this public policy (increase of pay auditing and agreements, monitoring tools of wage increases, awareness-training programs for managers); an uneven policy empowerment process (as only trade unions negotiators have access to bargaining table and data, in a very technical and conflictual “battle of figures”, cf. Pochic, Chappe, 2018) and finally its limited and selective direct or short-term outcomes (few budgets for women-only wage increase, beneficial mainly to white middle class women, in large firms and lucrative sectors, that can even re-create conflicts with trade unions on priority targets). We underline that a public policy based mainly on Pay transparency fails to reveal, by itself, the multiple causes and extent of gender pay gaps. It faces strong employers’ resistance to increase female workforce costs, particularly in times of economic restructuring and for pink collars. Its indirect or long-term outcomes (gender awareness, actions on gender job segregation or career promotion) are low. Public instruments (gender pay reporting, without a ‘comparable worth’ approach) can have a temporary effect on gender pay gaps, in some organizational contexts, but fail to change the structural and organizational causes of these gaps.