This dissertation consists of three chapters that study econometrics questions and their applications to education. Chapter 1 studies a nonparametric two-sided many-to-one matching model, where many agents on one side match one institution on the other side. Classical examples include student-college matching and firm-worker matching. In this paper, I study nonparametric identification and estimation of many-to-one matching with non-transferable utility. The existing literature either assumes that the matching algorithm and reported preferences are observed or that preferences are homogeneous. This paper assumes heterogeneous preferences on the two sides and only requires data on who matches with whom in a single large market. Under mild re...