The gender pay gap exists in every European country, but it varies even in EU states covered by the same legal principles on pay equality. Based on the EC funded research project "Close the Deal, Fill the Gap", this book uses an comparative interdisciplinary analysis to review the impact of social partnerships on GPG in Italy, Poland and the UK and provides guidelines for the negotiation of GPG-related issues. Essential for researchers and advanced students with an interest in the gender pay gap in collective bargaining processes as well as practitioners and policy makers in trade unions and employers’ associations.