Women around the world still earn just 77p for every pound that men earn. And only half of women are in paid employment in the first place. Despite this, women still work longer hours than men, because more often than not they bear the responsibility for household duties and caring for the family.
Today, double the number of women around the world cannot read than men, and girls are still more likely to never set foot in a classroom than boys. Women need equal access to economic and educational opportunities, and proper access to health care services. The evidence shows that when women get a better deal, it's not just women who gain - but also their families and wider communities.
Gender inequalities are often due to entrenched attitudes that can also deprive women of a say in what happens in their lives - and even to their own bodies. Over a third of women have experienced physical or sexual violence at some point in their lives.
Women are also deprived of a say in what happens in their countries. Less than a quarter of all Parliamentary seats are held by women, when it is women who suffer the most during periods of conflict and economic stress. Despite this, donor and domestic funding for women's empowerment is tiny in comparison with other priority areas.
The Robin Hood Tax could raise billions every to tackle discrimination and injustice, and help to make sure women get the fair deal they deserve.