Batch living-radical polymerization techniques were used to produce polymers with molecular weight distributions approaching the narrowness of truly living (ionic) systems. Continuous reactors may offer some advantages for living polymerization in copolymer morphology, but continuous polymerization with any level of backmixing will broaden the molecular weight distribution. This study used simple moment techniques to demonstrate that idealized living-radical polymerization in a single stirred tank reactor will have a polydispersity of 2. This is also the theoretical minimum polydispersity for a truly living polymerization. (C) 2004 Wiley Periodicals, Inc.