Logistic Regression Using SAS®: Theory and Application

8.6. Matching

In the postdoctoral example, the data was clustered into naturally occurring groups. Matching is another form of clustering in which individuals are grouped together by design. Matching was once commonly used in the social sciences to control for potentially confounding variables. Now, most researchers use some kind of regression procedure, primarily because of the difficulty of matching on several variables. However, with the recent development of the propensity score method, that objection to matching is largely obsolete (Rosenbaum and Rubin 1983, Smith 1997).

Here’s a typical application of the propensity score method. Imagine that your goal is to compare academic achievement of students in public and private schools, controlling ...