With funding from the Lumina Foundation, this project utilizes the demographic techniques of direct standardization and decomposition to assess the impact of several key demographic and family background characteristics on the change in the share of U.S. adults ages 25 to 64 with a postsecondary degree. Our methodology provides measures of the size and direction (increase or decrease) of the effects of these demographic and social factors on changes in the percent of adults with college degrees. Decomposing these effects separately by gender and race/ethnicity provides important information about which policies or programs may be most effective in increasing college completion for different gender and racial and ethnic groups in the future.