In this paper we extend Lizzeri's simple model of information transmission through certification intermediaries. A seller with no means to signal his quality has the possibility to be certified by an institution that owns a technology to discover the true quality and can credibly commit to a...

In this paper we address the question of collusion in mechanisms under asymmetric information. We develop a methodology to analyze collusion as an informed principal problem. First, if collusion occurs after the agents accept or reject the principal's offer; the dominant-strategy implementation...

In this paper we address the question of collusion in mechanisms under asymmetric information by assuming that one of the colluding parties offers a side contract to the other one. We develop a methodology to analyze collusion as an informed principal problem. We show that if collusion occurs...