A field experiment on financial incentives for short and long term gym attendance
This paper presents a field experiment to analyze whether financial incentives, conditional on attending the gym, can increase gym attendance of members of an off-campus gym both in the short run (two quarters of a year) and in the long run (the next two quarters of the year). The incentivized subjects received a rebate of approximately 10% of the average membership fee conditional on attending the gym at least once per week in 11 of the 13 weeks of the first quarter of 2010. In the second quarter of 2010 the incentive was repeated, allowing subjects a second chance to earn a rebate. In both quarters they received a rebate of €25 instead of €15 conditional on attending the gym at least twice a week in 11 of the 13 weeks. Gym attendance was recorded both during the intervention period, and during the two quarters after. We compared the conditional incentive to attend the gym with an unconditional incentive where subjects would receive the 10% rebate per quarter merely for staying a member of the gym. The conditional incentive to attend the gym had a positive, yet non-persistent, impact on gym attendance. We conclude that gym attendance can be improved through incentives, but that smarter (non-)financial incentives and nudges need to be explored as well to obtain more persistent improvements in gym attendance.