Polymerization processes comprising melt polymerizing a carbonate and a dihydroxy compound in the presence of an amount of a beta organic catalyst so as to give rise to a polycarbonate product, wherein the amount of beta organic catalyst comprises at least one onium salt and also comprises triphenyl phosphonium oxide (TPPO), and wherein the TPPO represents less than about 0.3 weight % of the sum of the weights of the at least one onium salt and the TPPO in the amount of beta organic catalyst.