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...

Recently, the combinatorial clock auction has become more and more common in the auctioning of telecommunication licenses. Although the auction design is complex, the promise is that bidding becomes simple - truthtelling is "close to optimal". We show that this claim is too strong. The auction...

Using the concept of Inequity Aversion we derive in a Moral Hazard setting several results which differ from conventional contract theory. Our three key insights are: First, inequity aversion plays a crucial role in the design of optimal contracts. Second, there is a strong tendency towards...