In the presence of utility penalties, collateral requirements do not always eliminate the occurrence of Ponzi schemes. Harsh utility penalties may induce effective payments over collateral recollection values. In this event, loans can be larger than collateral costs and Ponzi schemes become...

We prove the existence of monotonic pure strategy equilibrium for many kinds of asymmetric auctions with n bidders and unitary demands, interdependent values and independent types. The assumptions require monotonicity only in the own bidder's type. The payments can be a function of all bids....