Gresham's law states only one precondition: in the world of metal coins, if there is a fixed rate of exchange between good and bad money, then bad money will drive out good. We argue, however, that when there is <italic>no</italic> fixed exchange rate between good and bad money, and when the government...

In the last decade, the problem of getting a consensus group ranking from all users' ranking data has received increased attention due to its widespread applications. Previous research solved this problem by consolidating the opinions of all users, thereby obtaining an ordering list of all items...