A new fitness concept developed by two Harvard economics students, Yifan Zhang and Geoff Oberhofer, leans heavily on behavioral economics to motivate its members to workout. The concept, Gym-Pact, employs what Zhang calls “motivational fees” – members pay more money when the do not exercise. The students are trying to tackle a particular economic challenge: because gym fees are paid upfront, there is little future economic penalty for not working out. In effect, you’ve already paid the maximum economic penalty. Gym-Pact addresses this issue by linking your economic penalty/reward to your weekly workout schedule. For example, members currently pay up to $25 per week when they fail to exercise at least three times and $75 for dropping out of the program. Conversely, members who hit the gym at least four times per week pay nothing. (via Boston Globe)