Across the globe, women earn on average substantially less than men. The gender wage gap stands on average at 23 per cent – meaning that women earn 77 cents on every dollar earned by men for each hour worked. Worldwide estimates show that at current trends, gender differences in pay will not close until 2069 . This rate of change is unacceptable, and there is therefore a need for accelerated action to close the gender wage gap. This policy brief explains the reasons behind the gender gap – which include gender discrimination, the over representation of women in sectors and jobs that pay less, and penalties in pay and career progression due to parenthood. The brief also sets out the different policies that can be effective in tackling this gap, which include the establishment and enforcement of equal pay legislation, measures to reduce gender segregation in the labour market and increase the value of women’s work, policies to address women’s under representation in management, investments in the care economy, minimum living wages and strengthened collective bargaining.