A quarter century of experience with public/private competition in the Medicare program demonstrates that the private plans will not allow a level playing field. Despite strict regulation, private insurers have successfully cherry picked healthier seniors, and have exploited regional health spending differences to their advantage. They have progressively undermined the public plan — which started as the single payer for seniors and has now become a funding mechanism for HMOs — and a place to dump the unprofitably ill. A public plan option does not lead toward single payer, but toward the segregation of patients, with profitable ones in private plans and unprofitable ones in the public plan.
Source: Public plan option in a market of private plans by Dr. David Himmelstein, M.D. and Dr. Steffie Woolhandler, M.D., M.P.H.