Women, it turns out, work for free for two months a year as a result of the gender pay gap. It is as if women’s earnings – as compared to men's – are zero from November until the end of the year. When I say their earnings are nil, I am not referring to the vast quantities of unpaid work such as housework, child care or caring for the elderly and disabled. That is a whole conversation in itself, of course. According to UK-based charity group Oxfam, the value of that particular kind of unpaid labour of women, globally, was worth nearly $11 trillion in 2018. No, what we need to talk about is that even when they are in "paid employment", women individually and as a whole are earning far less. And not only is this completely unjust and wrong, it has ripple effects on autonomy, freedom and long-term empowerment of women. Equal pay is when men and women are paid the same amount for the same work. Countries around the world typically have legislation that enshrines the principles for same work, same pay. The reality, of course, doesn't always match up to the law. It's why in the UK, for example, there were nearly 30,000 equal pay tribunals in 2019, with women bringing claims of discrimination against their employers, according to figures from the Ministry of Justice. In the EU, women are paid 14.1 per cent less than men on average per hour. This equals almost two months of salary. Globally, the average hourly rate is 23 per cent less. Let that sink in, women are earning – in paid employment, not on a total average – nearly a quarter less than men. The gender pay gap is the percentage difference between average hourly earnings for all men and women in a company, sector or across the country. Not only does it encompass the differences between a man and a woman doing the same job, but it also includes a number of additional factors. For example, men have disproportionately more senior roles than women, and senior roles typically attract higher pay, whereas women have disproportionately more junior roles that attract lower pay. It also includes the fact that disproportionately more women do jobs in lower-paid sectors. A separate philosophical question is whether jobs undertaken by women are lower paid because they are considered "women's work" and, therefore, are valued much lower by societal and pay norms. What this points to when it comes to pay is that there are individual differences, but there are also systemic differences. The former is addressed by laws protecting equal pay. But the systemic differences are much more challenging and require us to ask "why" questions: why are the jobs that women disproportionately take up the lower-paid ones; why are those jobs paid so poorly; why do more mothers (rather than fathers) take career breaks beyond the early infant years after which there is no specific reason a woman is more capable than a man of child caring; and why is the expectation of part-time working more on women than men. While reading through these questions, you may have your own expectations and assumptions. Maybe there is an idea that women are "better suited" to caring roles than men. Or that society supposedly can't afford to pay those roles better. That women make better parents or that men are incapable. Or that it is supposedly a woman's duty to give up work and she is by evolution designed to stay at home. These are all, of course, rooted in existing societal norms: there is an expectation that it is perfectly fine to pay women less because their roles are of less value when it comes to paid employment, and that women should stop complaining because if they choose to work, then that comes with sacrifice. Except many women do not choose to work, they have to do so for themselves and their families. Except that if women do not have financial independence they can be trapped in toxic or abusive family situations because financially they simply cannot leave. Except that our society loses out on the talents of half the population by asserting these norms. Except the fact that mental health, self-development and fulfilment are the rights of women just as they are for men. And because, frankly, women are left high and dry as their lives progress with the early expectation that they will sacrifice for family and society, but with huge shortfalls later, as they age, when it comes to pensions, retirement and care in later life. There is a significant challenge to tackle these "why" questions because it means redressing norms and expectations at a societal level, but also within individual homes and families, where expectations of gender roles are particularly hard to change. All of that is before we even get to tackling the equally challenging questions of how to do this. The first step, of course, is to give the problem a name and to discuss its root causes. Because no-one should be working for free. Especially under the guise of paid employment.