This paper investigates whether the curricular structure of an Economics course (semester, trimester, or compressed block schedule) has an effect on an undergraduate's subsequent retention of course material. We test separately for theoretical/process comprehension and for graphical construction/interpretation, while separating micro from macro content as well. We use an instrument to address the no stakes testing problem, and our Heckman two-stage estimations present some interesting results for educators and institutional policymakers alike.