We compare two commonly used mechanisms in procurement: auctions and negotiations. The execution of the procurement mechanism is delegated to an agent of the buyer. The agent has private information about the buyer s preferences and may collude with one of the sellers. We provide a precise...

We analyze the bidding behavior in a strictly descending multi-unit auction where the price decreases continuously without going back to the initial start price once an object is sold. We prove that any equilibrium in the multi-unit descending auction is inefficient. We derive a symmetric...

We compare two commonly used mechanisms in procurement: auctions and negotiations. The execution of the procurement mechanism is delegated to an agent of the buyer. The agent has private information about the buyer’s preferences and may collude with one of the sellers. We provide a precise...

We compare the effects of information acquisition during a descending auction with its static counterpart, the first-price sealed-bid auction. In a framework with heterogeneous prior information, we show that an equilibrium with information acquisition exists in both auction formats. We show...

Since the seminal work by Rothschild and Stiglitz on competitive insurance markets under adverse selection the problem of non-existence of equilibrium hat puzzled many economists. In this paper we approach this problem from an evolutionary point of view. In a dynamic model insurance companies...

By offering or choosing a contract the informed agent might reveal information to the principal which could be used for immediate renegotiation. This is discussed in an axiomatic approach. We show that if, given the revealed information, there exists a contract which is preferred by everyone,...

If bidders can acquire information during the auction the descending auction is no longer equivalent to a first-price-sealed-bid auction. Revenue equivalence does not hold. The incentive to acquire information can even be larger in a descending auction than in an ascending auction.

We consider a regulator who does not know how many firms should be granted a license to enter a market as he has limited information on their setup costs. We propose two auction formats which implement the efficient market structure. In a "jumping English auction" the price for a license...