In this article, the author proposes an innovative, exam-based homework grading method to facilitate both collaboration among students and individual accountability while learning a complex theory and applying it to solve a problem. Results from this novel approach to grading a "comparative advantage theory" homework assignment, using an objective exam performance measure to adjust original homework grades, show that students increase their comprehension of the frequently misunderstood theory. This novel grading method can be applied in a variety of contexts to promote student collaboration in preparation of academic work while providing incentives to encourage individual accountability and engagement.