“My own choice of a single-variable measure for rapid and revealing comparisons of quality of life is infant mortality: the number of deaths during the first year of life that take place per 1,000 live births. Infant mortality is such a powerful indicator because low rates are impossible to achieve without having a combination of several critical conditions that define good quality of life—good healthcare in general, and appropriate prenatal, perinatal, and neonatal care in particular; proper maternal and infant nutrition; adequate and sanitary living conditions; and access to social support for disadvantaged families—and that are also predicated on relevant government and private spending, and on infrastructures and incomes that can maintain usage and access. A single variable thus captures a number of prerequisites for the near-universal survival of the most critical period of life: the first year.”