In the United States, education is widely thought of as the "great equalizer" (Mann 1848), functioning to improve economic and social status. Sociological literature, however, indicates that family background is a stronger predictor of student achievement than are schools themselves. In many cases, low socioeconomic status students have a disadvantage that cannot be overcome by schools, and family socioeconomic status, not merit, often determines student academic success. This research considers how family socioeconomic status, school factors, and structural characteristics of nations interact in order to produce educational stratification. It argues and finds support for the idea that since national social organization and government policy vary, the effects of socioeconomic status on achievement also vary on a cross-national basis. Moreover, the dissertation argues that certain social organization and governmental policies of nations create mechanisms by which socioeconomic status influences student achievement. These mechanisms have the potential to create circumstances whereby socioeconomically advantaged individuals are able to obtain greater benefits from schooling than their socioeconomically disadvantaged peers. The dissertation applies hierarchical linear models (HLM) to data from twenty-nine nations to explore how a number of structural characteristics of nations, including national education policy, social welfare policy, and societal inequality, influence the relationship between socioeconomic status and student achievement. Results confirm that policies and characteristics of nations do indeed have the potential to influence the relationship between socioeconomic status and student learning. Specifically, I find that countries with educational policies which aim to provide equal learning opportunities to all students have a weaker link between student socioeconomic status and learning outcomes, as do countries with more liberal social welfare policies. Further, I find that there is a curvilinear relationship in the effect of income inequality on the relationship between socioeconomic status and learning. These findings of strong macro-level influences on student achievement have the potential to advance the objective of equal educational opportunities for all students, as they suggest ways to break the link between socioeconomic background and learning outcomes.