Worker ownership of the means of production 
The first paragraph says that socialism is associated with "worker ownership" of the means of production. If that's the case, then the U.S. is socialist, because "About three quarters of all U.S. business firms have no payroll." As of 2002, the number of firms in the U.S. with no employees is 17,646,062. The number of firms with employees is 5,696,759.