Giving Compass' Take:

• A report from the World Bank estimates that ensuring that girls finish 12 years of quality education would result in an economic benefit of $15 trillion to $30 trillion each year. 

• What are effective ways to increase girls' access to education? How many girls are in ineffective schools? 

• Learn more about the cost of gender inequality. 

Failing to let girls finish their education could cost the world as much as $30 trillion in lost earnings and productivity annually, yet more than 130 million girls are out of school globally, the World Bank said.

Women who have completed secondary education are more likely to work and earn on average nearly twice as much as those with no schooling, according to a report by the World Bank.

About 132 million girls worldwide aged 6 to 17 do not attend school, while fewer than two-thirds of those in low-income nations finish primary school, and only a third finish lower secondary school, the World Bank said.

If every girl in the world finished 12 years of quality education, lifetime earnings for women could increase by $15 trillion to $30 trillion every year, according to the report.

Other positive impacts of completing secondary school education for girls include a reduction in child marriage, lower fertility rates in countries with high population growth, and reduced child mortality and malnutrition, the World Bank said.

"We cannot keep letting gender inequality get in the way of global progress," Kristalina Georgieva, World Bank chief executive, said in a statement.

Read the full article about the cost of not educating girls by Ellen Wulfhorst at Global Citizen.