“…Chiswick, 1971, Knight and Sabot, 1987, and Marin and Psacharopoulos, 1976 have pointed out that the effect of educational expansion on earnings inequality is difficult to predict a priori, depending on specific changes in different levels of schooling, the relationship between schooling and earnings, and the change in that relationship as schooling increases. Several studies, such as Winegarden (1979), Ram (1984), and Tilak (1989), have attempted to clarify the relationship empirically by estimating cross-national regressions of the relationship between income inequality and measures of mean schooling and schooling inequality. These cross-national estimates provide conflicting empirical results, however, and for a variety of reasons give only a limited picture of the relationship between changes in the distribution of schooling and changes in the distribution of earnings over time.…”