NEW YORK – The human costs of child marriage are well known; around the world, child brides are, on average, less educated, poorer, and more prone to sexual violence than women who marry later in life. But when the economic impact of child marriage is added to this grim tally, the bill is truly staggering.

According to the International Center for Research on Women and the World Bank, ending the practice of child marriage would save billions of dollars in annual welfare expenditures, resulting in global savings of more than $4 trillion by 2030. Simply put, the world cannot afford to allow child marriage to continue.

Many governments have already recognized this. In Indonesia, for example, where the economic impact of child marriage is negatively affecting long-term growth forecasts, President Joko Widodo has vowed to outlaw the practice, a significant pledge in a country where 14% of girls are married before their 18th birthday.

But in most countries where child marriage is prevalent, change is not occurring fast enough. While strategies have been discussed from Bangladesh to Zambia, funding for programs proven to reduce rates of child marriage – such as improving girls’ access to health care, education, and job training – remains inadequate. If ending child marriage is ever to be more than a political talking point, holistic strategies must be backed by financial commitments.

To be sure, the child-marriage challenge is immense. Today, roughly one in five girls worldwide is married or in an informal union before they turn 18, and most of these girls will become mothers before they reach adulthood. In Niger, which has the world’s highest rate of child marriage, 76% of girls are married before they can vote. And wherever child marriage occurs, girls often have little say in the decision.

The good news is that there has never been a better time to tackle this global problem. With the economic costs of child marriage now clear, governments in the developing world are beginning to address the issue with more urgency. To tip the scales, however, rich countries must be enlisted in the fight, and the next opportunity for them to engage is fast approaching.

On May 31, G7 finance and development ministers will hold the first of a series of meetings in Canada to discuss how economic growth can be more equitably shared. These meetings will pave the way for broader discussions next week, when Canadian Prime Minister Justin Trudeau hosts the full G7 summit.

Trudeau has already vowed to make gender equality a key theme at this year’s meeting, and we certainly welcome his focus. But we also recognize that unless G7 ministers match their words with dedicated funding, the summit’s lofty pledges will fall short – and children everywhere will continue to suffer the injustice of early marriage.

Ending child marriage will require ambition, creativity, and money. But that is just a start; targeted solutions are essential. While education is critical to girls’ futures, simply building schools and paying teachers will not be enough. To be fully empowered, girls need access to safe, quality education that gives them the confidence and skills to succeed. Achieving that will require long-term engagement.

If the world’s richest countries were to make this issue a high priority, the payoffs would be significant. For example, the World Bank estimates that if Niger could ban child marriage, it would realize annual welfare savings in the vicinity of $1.7 billion. Bangladesh could generate an additional $4.8 billion in annual earnings and productivity, and welfare savings in Nigeria would total $7.6 billion.

Governments are starting to make strides in reducing rates of child marriage; in fact, the number of girls married as children each year is declining. Unfortunately, change is happening too slowly. If the world does not dramatically accelerate progress and scale up investments, rapid population growth will reverse current gains, and the number of child brides will grow once more.

Girls can change the world, but at the moment, circumstances beyond their control are limiting their potential. When G7 ministers meet this week and next, one theme they will discuss is "investing in growth that works for everyone.” From our perspective, the best way to translate that goal into reality is by addressing a social ill that generates huge costs – and not just for girls.

The writer is the Executive Director of the United Nations Children’s Fund (UNICEF).

Copyright: Project Syndicate.