Valuing undesirable waiting time: Evidence from a real-incentive lab experiment

We study how individuals value reductions in passive and undesirable waiting time using a real-incentive laboratory experiment. Participants were required to endure enforced inactivity – no phone, no reading, no conversation – and could pay to reduce the waiting time. By varying both the size of the time reduction (within-subject) and the initial waiting duration (between-subjects), we elicit willingness to pay (WTP) for time savings and compute the implied value of time (VOT) in euros per hour. We find that WTP is positive on average but increases less than proportionally with the amount of time saved. As a result, the VOT decreases with both the size of the time reduction and the initial waiting time. These findings highlight reference dependence and diminishing marginal sensitivity to time savings, challenging the assumption of a constant VOT commonly used in transport appraisal. Our results support a more context-sensitive approach to time valuation.