During the second half of the twentieth century, a process of privatization took place in the Argentine education system. This paper seeks to explain the growth of private enrollments in Argentina over the last years. Drawing on the concept of quasi-monopoly, we run a random-effects estimation on panel data to analyze the determinants of the complex (and dynamic) equilibrium between public and private education supply. It is observed that the behavior of both sectors is explained by (1) the incorporation of new students to the education system, (2) the State action regulating and financing, and (3) the general socioeconomic conditions.