Gross enrollment ratio is defined by the United Nations Educational, Scientific and Cultural Organization as a nation's total enrollment "in a specific level of education, regardless of age, expressed as a percentage of the population in the official age group corresponding to this level of education." The statistical measure determines the number of students enrolled in school at several different grade levels (such as elementary, middle school and high school), and compares it to the number of students who live in that country who qualify for the grade level.
To calculate the gross enrollment ratio, a country uses a simple formula: the country divides the number of children and young adults who are of school age by the number of individuals who are actually enrolled in school. For example, if a nation has 150,000 people enrolled in school, this number is divided by the total number of school-age individuals. If this number is 200,000, 75 percent of the people are enrolled.
The United Nations uses all levels of education to create the Human Development Index. The index is used to measure countries in the U.N. by their level of human development. In addition to the gross enrollment index, the index measures literacy, standards of living and life expectancy. Using these categories, the U.N. is able to measure the well-being of the countries' inhabitants, especially children.
By looking at the gross enrollment ratio and the human development index, the United Nations can determine which nations are developed, developing or underdeveloped. Countries with a low GER are likely underdeveloped, with their youth lacking the education and skills needed to thrive. Factors such as standard of living, access to schools and a low income (determined by gross domestic product per capita) can drive the GER to very low levels.