The new decade has been called "the age of information." We show that, although information has become more accessible, the increase in the variety of products has made consumers' choices complex and uncertain. Faced with uncertainty about products' attributes offered by "umbrella brands,"...

n this paper we investigate the implementation problem arising when some of the players are ``faulty" in the sense that they fail to act optimally. The exact number and identity of the faulty players is unknown to the planner and to the nonfaulty players, but it is common knowledge that there...