This paper shows that the possibility of collusion between an agent and a supervisor imposes no restrictions on the set of implementable social choice functions (SCF) and associated payoff vectors. Any SCF and any payoff profile that are implementable if the supervisor's information was public...

In Buy-It-Now (BIN, hereafter) auctions, sellers can make a "take-it-or-leave-it" price offer (BIN price) prior to an auction. We analyse experimentally how eBay sellers set BIN prices and whether they benefit from offering them. Using the real eBay environment in the laboratory, we find that...

Overbidding in sealed-bid second-price auctions (SPAs) has been shown to be persistent and associated with cognitive ability. We study experimentally to what extent cross-game learning can reduce overbidding in SPAs, taking into account cognitive skills. Employing an order-balanced design, we...

Overbidding in auctions has been attributed to e.g. risk aversion, loser regret, level-k, and cursedness, relying on varying identifying assumptions. I argue that "type projection" organizes these findings and largely captures observed behavior. Type projection formally models that people tend...

We show that it is beneficial for a buyer to conduct a multi-stage mechanism if bidders are loss averse. In a first step, we derive a revenue equivalence principle. Fixing the multi-stage structure, the revenue is independent of the chosen payment rule. Secondly, we introduce a simple two-stage...