10/11/2016 03:56 GMT | Updated 11/11/2017 05:12 GMT

The Pay Gap: Not Damned Lies, But Statistics

Chris Ratcliffe via Getty Images

And so November rolls around again, with fireworks, falling leaves and ferocious arguments about the pay gap.

Yes, it's the time of year to mark Equal Pay Day, when some people suggest we should pay women the same as men and others shout about women "choosing" to earn less because they prefer not to get their hands dirty and to look after children instead. (Of all the elements of this argument, the contradiction in that last point baffles me every time.)

As one who spends a fair bit of time embroiled in this debate, I like to think the people claiming the pay gap is a myth aren't simply doing a Donald - ie lying to deny what they know to be true. I think the confusion arises because too often, when we talk about the pay gap, there's a misunderstanding that we're talking about one single form of discrimination. And so people jump in to disagree about the extent to which that one form of discrimination happens.

Oh, to have only one layer of discrimination to fix. We could sort this out before tea and still have time to argue about whether we need an International Men's Day. (Heads up: that one's for next week.)

But we're not talking about one single form of discrimination. We're talking about layers and layers of it. That's why the 9% full-time pay gap figure isn't an appropriate number to use. And that's why the 14% part-time pay gap figure isn't right either. Those multiple layers are why the pay gap between women and men is 19%. And those layers intersect with other forms of discrimination to drive a 22% pay gap for disabled women, and a 23% pay gap in hourly earnings between black and white graduates.

It's time to have a much bigger conversation about what we do to close that gap.

The pay gap doesn't just stem from discrimination via a sexist boss or HR department. It also stems from an education system that creates occupational segregation - the discrimination that funnels boys into highly-paid STEM careers while girls are funnelled into clerical, catering or caring roles with lower economic output. And it also stems from the discrimination of a society that doesn't value care, puts the burden of it on women, and then pushes them out of the workplace when they become parents or supporters of elderly relatives.

As a result, not only is the pay gap nearly 20 percent, but so is the productivity gap between us and most other G7 countries. On top of that we have some of the most expensive childcare in the Western world. Unless we fix all of those things we are all - women and men - in trouble. Because this isn't simply an argument about paying women more. We're not passing the hat for tips - though I might prefer busking to having this argument for the next 53 years. We need women to work and contribute to the economy so that everyone benefits from stronger economic growth.

It's a problem that can't be fixed by existing, limited legislation on equal pay. We need a three-part approach to tackle a three-part problem. So today the Women's Equality Party launches its #TripleWhammy campaign to: end workplace discrimination by publishing pay data that shows a full breakdown of gender, race and disability and includes retention rates before and after maternity leave, and restoring the right to bring dual discrimination claims; build a more equal education system by making schools' approach to gender equality measurable by Ofsted and overhauling careers advice; and invest in equal care by offering paternity leave at 90 percent of pay as well as government-funded childcare from the end of parental leave at nine months.

Today's debate is a bit of a game for some people; social media meninists and radio shock jocks will ask - in synthetically sympathetic tones - whether this isn't just a fuss over nothing. But the pay gap isn't a generational overhang and it isn't going away any time soon. Discrimination isn't a game. Poverty isn't a game. And a hamstrung post-EU economy isn't something any of us should take lightly.