The public goods nature of social infrastructure spending—that is, the positive eternality economies experience in response to such spending—reflects the benefits that accrue to broader society as well as the individual. Much more empirical work is needed to identify its quantitative impact on long-run productivity growth.8 There is, however, already substantial evidence that social infrastructure spending that addresses key intergroup inequalities has sizeable beneficial economy-wide effects. Several studies provide evidence that closing the education gap between boys and girls has a positive effect on economic growth (Klasen and Lammana 2009: Bandara 2015).