This book provides a careful historical analysis of the co-evolution of educational attainment and the wage structure in the United States through the twentieth century. During the first eight decades of the twentieth century, the increase of educated workers was higher than the demand for them. This boosted income for most people and lowered inequality. However, the reverse has been true since about 1980. The authors discuss the complex reasons for this educational slow-down and what might be done to ameliorate it.