PRA money STAYS -your- money,all the time. No empty promises.it earns interest,grows your wealth.
In Soc.Security,your money becomes THEIR money,and it MIGHT be repaid. No guarantees.
Plus,the "investment" FEDGOV does with SS is in gov't bonds,meaning that somebody is going to be -taxed more- in the future to pay that "interest",because FEDGOV generates NO profit. it's ALL overhead,a loss. Higher taxes are a drain on the economy.