We develop a dynamic economic model based on contemporary understanding of learning and motivation. The model and resulting comparative static analysis show the instructor's role in providing a productive learning environment. Instructors should set the complexity of course assignments and assessments to be consistent with student preparedness. Learning is enhanced when the rate of change in challenge is based on the rate of change of how rapidly students are learning. Instructors steer students toward a productive trajectory with tasks that cause students to work hard and by consistently providing feedback and fostering a culture of learning.
