Factors that have contributed to the increase in college enrollment since 1978 and the possible impact of these factors on future college enrollments were analyzed using data from the Higher Education General Information Survey and the Current Population Survey. During 1978-1984, enrollment increased despite declines in the 18- to 24-year-old population. While the major factor in the enrollment increases since 1978 has been higher enrollment rates for 18- to 24-year-olds, another factor has been increased enrollment by women, particularly those 25 years old and older. Implications for the future include the fact that enrollment rates for women 25 years old and older may decline as more women attend college prior to the age of 25. In addition, the enrollment rate for 18- to 24-year-olds may decline as higher proportions of college-age persons come from groups with traditionally lower college-going rates. Therefore, while enrollments have remained high in the early 1980s, a decline in the late 1980s and the early 1990s may occur. Trends in enrollment are reported by gender, age, age by gender, and race/ethnicity (White, Black, and Hispanic). Information on college enrollment estimation and the reliability of estimates is appended. (SW)