Identifying societal and economic factors that have an influence on sustainability courses is of great importance for grappling environmentally challenging issues. Education has long been seen as an effective method to efficaciously diffuse knowledge, values, and behaviors that help to better protect the environment, as well as promote ecological awareness. In order to promote environmental education, establishing environmental courses is paramount. This paper presents significant findings that showcase the discrepancy between the total number of environmental classes offered at the top 20 universities and the rest of the non-top-tier universities located throughout South Korea. Within the groups, there are subgroups organized by Seoul-based areas and non-Seoul-based ones. The purpose of the groups is to estimate heterogeneous coefficients of total sustainability classes at Seoul-based top universities and non-Seoul-based-top ones, respectively. A comparison by locations shows that Seoul-based-top universities and non-Seoul-based-top universities bear a striking distinction in total sustainability classes per semester. Immense discrepancies are also found between the number of environmental classes offered at prestigious and lesser prestigious universities exist particularly in non-Seoul areas. Result from a comparison by different ownerships indicates evidence of heterogeneity across types of ownership.