This paper studies the vulnerability of the pivotal mechanism with respect to manipulation by groups. In a lab experiment, groups decide on the implementation of various alternatives, some of which imply opposite interests for the two subgroups. We investigate the occurrence of tacit and...

We experimentally examine the collusive properties of two commonly used auctions: the English auction (EN) and the first-price sealed-bid auction (FPSB). In theory, both tacit and overt collusion are always incentive compatible in EN while both can be incentive compatible in FPSB if the auction...

We study the effects of communication in an experimental tournament between teams. When teams, rather than individuals, compete for a prize there is a need for intra-team coordination in order to win the inter-team competition. Introducing communication in such situations may have ambiguous...