Recently human capital has emerged as one of the most active areas of research in economics. This research depends fundamentally on good data, and efforts at constructing useful measures of educational attainment for a broad panel of countries go back 20 years. In this book the extend the earlier work is extended by presenting and discussing a new long-term data set on educational attainment of the population for 146 countries from 1870 to 2010. In addition, new data is given on educational quality based on internationally comparable test scores for 134 countries from 1965 to 2010.