Before revision: A stable matching between two sets of agents (such as students and colleges) has received a great deal of attention in the literature. For an empirical study of matching markets, the main statistics of interest are  the matching frequencies, which show the fraction of students of a given type who match with colleges of a given type.
After revision: In an empirical study of matching markets, the main statistics of interest are the matching frequencies, which show the fraction of students of a given type who match with colleges of a given type.