Baicker, K., and Helen Levy. 2012. "The insurance value of Medicare." The New England Journal of Medicine, 367(19): 1773-5.
Medicare should provide access to care and protection from catastrophic spending while not being so generous that beneficiaries overconsume low-value care, thus driving up costs. Setting cost sharing is a balancing act that the Medicare program doesn't perform very well.
PMCID: PMC3726035. (Pub Med Central)