This paper examines price formation in a posted-offer market designed to simulate concert ticket resale platforms, where sellers set prices and buyers decide whether to accept them without negotiation. The experiment was conducted using VeconLab with 36 student participants across eight trading rounds. Randomly assigned buyer values and seller costs allowed for the construction of theoretical supply and demand curves and a predicted competitive equilibrium. Transaction prices increased over the course of the experiment, but most trades occurred below the theoretical equilibrium price and overall market efficiency was approximately 75 percent. This result differs from prior posted-offer market experiments, where prices typically exceed equilibrium. The divergence is likely explained by violations of the monotonicity, salience, and dominance precepts of induced value theory due to the use of extra credit rather than monetary incentives and the remote experimental environment.
