Selectivity of target samples.

The vast majority of research on student learning is based on assessments of student knowledge given during or at the end of an academic term. Until now, we have known very little about what knowledge students retain after a course is over or what determines how much they retain. In this paper, we analyze data collected from students who took one of six courses in introductory or intermediate microeconomics. All students in these courses took a low-stakes standard assessment of their learning at the end of the term. At follow-ups, one to 2.5 years later, these students were surveyed about their academic and job-related activities, and given the same assessment they took at the end of the course. We find that some demographic characteristics and prior preparation for the course are strong predictors of how much students retain while initial attitudes toward economics are not. We also find evidence that for some students, application of economic skills in subsequent jobs and courses helps students retain course skills.