In areas like voting, charitable giving and civic engagement, graduates of the program lag behind those who were accepted but declined and those who dropped out before completing their two years, according to Doug McAdam, a sociologist at Stanford University, who conducted the study with a colleague, Cynthia Brandt.
The reasons for the lower rates of civic involvement, Professor McAdam said, include not only exhaustion and burnout, but also disillusionment with Teach for America’s approach to the issue of educational inequity, among other factors.
The study used a survey to compare the three types of individuals. Yet there are reasons why some individuals decline an offer for Teach for America and others accept it. By definition, they had a better alternative, while those who accepted did not. That in and of itself signals that they are different and not comparable. Similarly there are reasons individuals drop out. To pretend that all three types are the exact same save for some random outcome is a ludicrous conjecture on its face.
If the study wanted to be causal, it would have to use an instrumental variable approach, or randomized trial, or natural experiment. All the study does is to examine sample selection, and is not causal in the least.