As we celebrate International Women’s Day on March 8th, working towards gender parity remains a moral imperative—but the economic case for doing so is also unequivocal. With respect to the latter, a 2015 study by the McKinsey Global Institute found that in a “full-potential” scenario, where women participate in the economy identically to men, US$28trn could be added to annual global GDP by 2025. In a less ambitious “best-in-region” scenario, where all countries match the rate of improvement of the best-performing country in their region, this would still equate to an additional US$12trn to annual global GDP by 2025.

The encouraging headline is that significant and steady progress has been made towards gender equality over the past 50 years. A World Bank report highlights a constant and positive direction of travel since 1970 on eight key indicators, including mobility, workplace, pay, assets and pensions, marriage, parenthood and entrepreneurship. This bodes well for the central tenet of UN Sustainable Development Goal 5 (SDG 5): to eliminate all forms of discrimination and violence against women and girls and achieve gender equality by 2030.

However, while there have been relative improvements over the past half-century, gender inequality remains rife.

Let’s focus on just one of the injustices faced by women today: the scourge of child marriage, which is specifically targeted in SDG 5.3 for elimination by 2030.

There are currently 650m women who were married as children worldwide. Twelve million girls per year are married before they reach their 18th birthday. That equates to roughly 33,000 girls per day, or one girl every two seconds. In Niger, three out of four women are married under the age of 18, and one in four under the age of 15.

For many of these girls, life changes drastically and detrimentally after marriage. Many are no longer allowed to go to school; many are forced to live in settings where domestic and sexual abuse are ever-present and in which their mental health is at stake; and as adolescents they experience higher risks of maternal mortality. The list goes on.

It isn’t solely the consequences of child marriage that are multifaceted and complex. So too are its drivers and incentives. Tradition, poverty, fear of sexuality—these are all part of the equation.

As Mabel van Oranje—an advocate against child marriage and founder of the “Girls Not Brides” and “Vow to End Child Marriage” initiatives—points out, the causes of child marriage vary widely across regions. It is therefore imperative to engage with communities on a local level to find solutions to the problem.

When I recently interviewed Mabel van Oranje on The Do One Better! Podcast, she shed light on the causes of child marriage and its various iterations in different locations.

“In some cases you see it’s related to poverty,” she explains. “So, for example, in India, if you’re poor there’s an incentive to marry your daughter at a young age because the family of the girl has to pay a dowry to the family of the boy, and the older the girl and the better educated she is the higher the dowry is.” 

By contrast, “in Africa you sometimes see in some communities a payment going the other way around, so the family of the boy pays cattle or another price to the family of the girl, so if you’re poor, marrying your daughter off means one less mouth to feed and maybe getting some cattle so you can more easily feed the rest of the family”.

The drivers of child marriage are numerous, but Mabel stresses that “whatever the reason why child marriage happens, what we see is that it is always to do with gender inequality. It’s always that idea that a girl is less than a boy, or that a girl is a burden and you want to get rid of her as quickly as you can”.

It’s easy to be daunted by facts and figures that highlight just how unsatisfactory and painful today’s reality is for millions of girls and women.

Child marriage is a global problem that is not exclusively found in the developing world. Indeed, it exists in high-income countries such as the UK, US and other jurisdictions that might not immediately or instinctively come to mind.

More than 200,000 children under the age of 18 were married in the US between 2000 and 2015. Most of the 50 States have an exception in law that allows children to marry before they turn 18. In the EU, only a handful of countries tolerate no exceptions to the minimum age of 18 for marriage.

If we are to end child marriage by 2030, progress on a global level needs to be 12 times faster than that of the past decade.

Encouragingly, there are many ways for us to support efforts to eliminate child marriage and fight for gender equality irrespective of whether we are individuals, charities, corporates or policymakers. These include writing to your government representatives, supporting organisations such as Girls Not Brides and advocating for change wherever the opportunity arises.

The campaign theme for International Women’s Day 2020 is #EachforEqual—there’s a focus on our individual actions and their impact. And when individuals come together, we can collectively help to create a gender-equal world.

Wherever we live and regardless of our gender, or that of our children, we should give child marriage and gender equality our undivided attention. We cannot achieve gender parity unless we end child marriage, and our economies will perform sub-optimally until we do so. The moral and economic arguments are robust, compelling and deserve our attention as we celebrate International Women’s Day on 8th March 2020.

Disclaimer: The views and opinions expressed in this article are those of the authors and do not necessarily reflect the views of The Economist Intelligence Unit Limited (EIU) or any other member of The Economist Group. The Economist Group (including the EIU) cannot accept any responsibility or liability for reliance by any person on this article or any of the information, opinions or conclusions set out in the article.