An Experimental Study on Sequential Auctions with Privately Known Capacities

We experimentally study bidding behavior in sequential first-price procurement auctions where bidders' capacity constraints are private information. Treatment differs in the ex-ante probability distribution of sellers' capacities and in the (exogenous) probability that the second auction is actually implemented. Our results show that: (i) bidding behavior in the second auction conforms with sequential rationality; (ii) while first auction's bids negatively depend on capacity, bidders seem unable to recognize this link when, at the end of the first auction, they state their beliefs on the opponent's capacity. To rationalize this inconsistency between bids and beliefs, we conjecture that bidding in the first auction is also affected by a hidden, behavioral type – related to the strategic sophistication of bidders – that obfuscates the link between capacity and bids. Building on this intuition, we show that a simple level-k model may help explain the inconsistency