Proponents of Single-Payer health care have attempted to recast health care from a product into a "public good." In fact, the term, "public good" has a very specific meaning in economics. While certain elements of health care may meet the definition, most - and the most interesting for public policy - do not.
In order to be a public good, an item has to 1) be non-rival, i.e., if I take some, it doesn't mean any less for you, and 2) non-excludable, i.e., effectively, you can't keep me from taking as much as I want. Air is a good example (despite the appealing military term, "oxygen thief").
Almost no medical services meet these requirements. There is no reasonable way that a hospital room, or the attention of the nurses assigned to that floor, can be either non-rival or non-excludable. Even if you pack patients in as though hospitals were tenements, there's still a limit. And I had darned well better know who's in each room, otherwise delivering care of any kind is going to be a pretty dicey proposition.
One could make a case that routine medicines such as aspirin and penicillin might, as well as most common vaccines. Even in those cases, however, one assumes need. While we can all breathe as much as we like, if all of us were to wander through hospital dispensaries gathering up handfuls of band-aids and anti-inflammatories, the stocks wouldn't last very long.
So someone saying that health care is a "public good," either doesn't understand the term - indicating a level of economic illiteracy and muddled thinking typical of so much of what passes for health care debate - or they do know, in which case their proposals have devastating implications.
