Ahead of Day of the Girl child this year, World Vision has created a Girls’ Opportunity Index, which explores what opportunities girls can expect to have in the 20 countries with the highest rates of child marriage worldwide, and analysed the relationship between these opportunities and their likelihood of marrying before their 18th birthday. Opportunity, as conceived in this index, is based on a girl’s well-being and access to healthcare, education, ability to make choices for herself, ability to work and manage her own money, and legal rights and representation. Around the world, girls are subject to a vicious cycle in which those living in contexts with little opportunity are more prone to child marriage, which in turn leads to fewer opportunities for not only them, but their children, too.