Chapter 8. Dropouts and Diplomas : The Divergence in Collegiate Outcomes Although collegiate attainment rates have risen in many developed and developing countries over the last three decades they have remained essentially flat in the United States over the same period. In this chapter we distinguish various models of degree attainment in the general context of theoretical and empirical specifications of educational attainment. To explain collegiate degree attainment we consider the roles of student demand the supply side of the postsecondary education market and the role of public support in determining outcomes. Although the study of college degree attainment has traditionally focused on demand side determinants of attainment including how students finance college attainment and academic preparation we present here the evidence that supply side determinants including the level of public subsidies and the associated stratification among colleges and universities are also important determinants of degree attainment. Review of this evidence and research suggests a number of unexplored areas for economic research related to college choice in college attainment and the supply side determinants of stratification and resources per student.