Since it was introduced in 2007, holistic admissions have been one of the most controversial policies in Korea. In 2007, the Korean government launched the Admissions Officer Project and selected leading institutions to administer holistic admissions in reviewing their applicants. The selected institutions received financial assistance for implementing holistic admissions and were subject to government control including enrollment monitoring and compliance with guidelines. Holistic admissions have diffused widely even among the institutions not receiving the government grant that about two-thirds of entire four-year colleges and universities administer them as of 2016. While holistic admissions is prevalent in the Korean higher education system after 15-years of effort, now it is also faced with significant controversies about its fairness and impact on students' access. In this dissertation, I examine whether the adoption of holistic admissions at the institutions, either unsubsidized or subsidized by the government, changes the composition of entering student body. To do so, I analyze data from the Higher Education Statistics Survey, which is a panel-type administrative data. In terms of analysis, I employ difference-in-differences to estimate the treatment effect of policy adoption at the subsidized and unsubsidized institutions. I also examine whether the government's monitoring of the enrollment of disadvantaged students at subsidized institutions affected the enrollment of this student group. Finally, I examine heterogeneity in the effect of holistic admissions adoption by institutional selectivity. I find that, in general, there is no significant change in the overall enrollments after the adoption of holistic admissions. The government's imposition of enrollment monitoring even had an adverse effect of decreasing the proportion of traditional high school students enrolling at the subsidized institutions. Further, the subsidized institutions enrolled significantly more selective high school students after the monitoring began. The adoption of holistic admissions also produced heterogeneous effects by institutional selectivity. Among Seoul institutions, that are mostly selective, unsubsidized adopters with the highest degree of implementation experienced a 6.3 percentage point increase in the proportion of graduates from selective high schools after adopting holistic admissions. The results from this study suggest that without a carefully designed monitoring and rewarding system accounting for institutional contexts, characteristics, and capacities, holistic admissions may be a mechanism that widens the gap in student access. Given the conflicting goals that the government, institutions, and society may have regarding college admissions, the success of holistic admissions in improving student access and success depends on whether society and institutions value these goals, and how the government designs admissions policies to reduce agency problems and motivate the institutions to achieve not only their own, but also social goals. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]