Some cities have bus systems that are free to use. In these cities, if the buses are not crowded, bus rides are However, if the buses are crowded, one person's use would make it so that another person could not "consume" the service. In this case, bus rides are In cities that charge a fare for bus riders, rides on buses that are not crowded are and rides on buses that are crowded are v private goods public goods common resources club (artificially scarce) goods