In auction and mechanism design, Myerson's classical regularity condition is often too weak for a quantitative analysis of performance. For instance, ratios between revenue and welfare, or sales probabilities may vanish at the boundary of Myerson regularity. This paper introduces L-regularity as...

We conducted a controlled field experiment on eBay and examined to what extent both social and competitive laboratory behavior is robust to institutionally complex real world markets with experienced traders, who selected themselves into these markets. EBay's natural trading system provides...

Many Internet markets rely on feedback systems', essentially social networks of reputation, to facilitate trust and trustworthiness in anonymous transactions. Market competition creates incentives that arguably may enhance or curb the effectiveness of these systems. We investigate how different...

Winning bidders in online auctions frequently fail to complete the transaction. Because enforcing bids usually is too costly, auction platforms often allow sellers to make a "secondchance" offer to the second highest bidder, to buy at the bid price of this bidder, and let sellers leave negative...

Winners in online auctions frequently fail to complete purchases. Major auction platforms therefore allow "second-chance" offers, where the runner-up bidder pays his own bid price, and they let sellers leave negative feedback on buyers who default. We show theoretically that (i) all else equal,...

Auctions are the allocation-mechanisms of choice whenever goods and information in markets are scarce. Therefore, understanding how information affects welfare and revenues in these markets is of fundamental interest. We introduce new statistical concepts, k- and k-m-dispersion, for...

Auctions are the allocation-mechanisms of choice whenever goods and information in markets are scarce. Therefore, understanding how information affects welfare and revenues in these markets is of fundamental interest. We introduce new statistical concepts, k- and k-m-dispersion, for...