Women are currently the majority of U.S. college students and of those receiving a bachelor's degree, but were 39 percent of undergraduates in 1960. We use three longitudinal data sets of high school graduates in 1957, 1972, and 1992 to understand the narrowing of the gender gap in college and its reversal. From 1972 to 1992 high school girls narrowed the gap with boys in math and science course taking and in achievement test scores. These variables, which we term the proximate determinants, can account for 30 to 60 percent of the relative increase in women's college completion rate. Behind these changes were several others: the future work expectations of young women increased greatly between 1968 and 1979 and the age at first marriage for college graduate women rose by 2.5 years in the 1970s, allowing them to be more serious students. The reversal of the college gender gap, rather than just its elimination, was due in part to the persistence of behavioral and developmental differences between males and females.

The history of coeducation in U.S. higher education is explored through an analysis of a database containing information on all institutions offering four-year undergraduate degrees that operated in 1897, 1924, 1934, or 1980, most of which still exist today. These data reveal surprises about the timing of coeducation and the reasons for its increase. Rather than being episodic and caused by financial pressures brought about by wars and recessions, the process of switching from single-sex to coeducational colleges was relatively continuous from 1835 to the 1950s before it accelerated (especially for Catholic institutions) in the 1960s and 1970s. We explore the empirical implications of a model of switching from single-sex education to coeducation in which schools that become coeducational lose donations from existing alumni. But by raising the quality of new students, a switch to coeducation increases other future revenues. We find that older and private single-sex institutions were slower to become coeducational and that institutions persisting as single sex into the 1970s had lower enrollment growth in the late 1960s and early 1970s than those that switched earlier. We also find that access to coeducational institutions in the first half of the twentieth century was associated with increased women’s educational attainment. Coeducation mattered to women's education throughout U.S. history and it mattered to a greater extent in the more distant past than in the more recent and celebrated period of change.

Private for-profit institutions have been the fastest-growing part of the U.S. higher education sector. For-profit enrollment increased from 0.2 percent to 9.1 percent of total enrollment in degree-granting schools from 1970 to 2009, and for-profit institutions account for the majority of enrollments in non-degree-granting postsecondary schools. We describe the schools, students, and programs in the for-profit higher education sector, its phenomenal recent growth, and its relationship to the federal and state governments. Using the 2004 to 2009 Beginning Postsecondary Students (BPS) longitudinal survey, we assess outcomes of a recent cohort of first-time undergraduates who attended for-profits relative to comparable students who attended community colleges or other public or private non-profit institutions. We find that relative to these other institutions, for-profits educate a larger fraction of minority, disadvantaged, and older students, and they have greater success at retaining students in their first year and getting them to complete short programs at the certificate and AA levels. But we also find that for-profit students end up with higher unemployment and "idleness" rates and lower earnings six years after entering programs than do comparable students from other schools and that, not surprisingly, they have far greater default rates on their loans.