That's just.....completely wrong.
https://en.wikipedia.org/wiki/List_of_countries_by_total_health_expenditure_per_capita
Medicare has lower overhead costs than private insurance (politifact rates the claim half true because the person claimed higher costs for private insurance than actual estimates but private still had 5x the admin cost):
http://www.politifact.com/truth-o-m...a-boxer-says-medicare-overhead-far-lower-pri/
So we've eliminated your argument that single payer isn't cost effective - it is in the United States and everywhere else in the world. "Effectiveness" is pretty subjective but the WHO list certainly had us below a lot of people.
Flaw, you have made some good points. First, you are correct, a single provider will definitely be more effective administratively. Even with government mismanagement, how could it not be. No longer having state insurance requirements and effectively combining hundreds of insurance companies into one. Also, eliminating all the claims burocracy. There would also be better access to individuals. That goes without saying. If everyone is covered, then you automatically have better access.
However, there are where the flaws come into the WHO report. Ratings were determined on 4 categories, two of which are access and administrative efficiency. By definition single payer/socialized healthcare is going to be superior in these categories. No matter what we in the US do to improve healthcare absent universal healthcare, we can never be as efficient or as available. My point is that the rating is flawed (no pun intended) because we can't compete on these categories unless we become a single provider system. That is, we could provide free preventive care to all and build hospitals in every neighborhood, but we'd still fall last on that list. It's like comparing apples and oranges, but with the caveat that apples are always better.
Now if you look at he quality of care category, you will see that the US fared much better - generally in the 3 and 4 range. Certainly there is room for improvement there, but it does not mean a single provider system is better. One of the factors pointed out is that Americans simply have less healthy lifestyles than our European counterparts and this was counted as a negative in healthcare.
So why is our cost for healthcare more? There are a number of reasons. As you pointed out, Our system is less efficient and that can be imprivved on. For example, the current legislation proposes an end to state autonomy over health carriers. However, when compared to a governmental ssystem (like in the U.K. Or Canada), the excess bureaucracy does offset somewhat our private inefficiency. My point is that this is not where the excessive cost comes from. These costs come from our lifestyle, mandatory health services, litigation mentality, medical innovation, and the way we perceive and expect healthcare benefits to be provided (see my earlier post on this), and these issues don't go away by simply implementing a a single provider system. So, implementation of a single provider system will move us up on the WHO list, but it won't solve many of the underlying issues and could (imho would) make them worse.
However, none of that is why we are not going to a single provider system. The real reason is taxes. The U.K. Has the #1 health system in the world by the WHO report. However that does not take into account the separate individual supplementary policies provided to executive level employees and the wealthy. It's basically like paying taxes for public school and sending your kids to private school. This increases care but also alleviates the strain on the system. Again, I see this as a flaw in the report.
The bigger issue is taxes. Every citizen in the U.K.that earns income pays taxes for healthcare. To get an equivalent program in the US we would have to tax every income earner approximately 20% on earnings. However, 45% of our citizens earn under the min poverty level and don't pay taxes. We would either have to start taxing them or move the burden to yhe middle and upper classes. There is no way an administration could increase taxes for this group that's effectively getting free coverage now and is generally living paycheck to paycheck and expect to be re elected. So that amount would have to be paid by others. A conservative estimate is an increase of approximately 25% for every middle an upper income wage earner. So, if you are paying 34% in taxes now, you could be looking at 59% and even higher for Larger income earners. There is a reason why John Lennon wanted to become a US citizen. The other alternative is to tax businesses, which has the effect of stifling the economy, especially small businesses which were made exempt from the mandates under the ACA for this reason.
There are many other reasons our costs will be higher than the UKs. We have a diverse population many of which are located in rural areas. That means more hospitals, doctors, nurses, equipment, etc for fewer people. We also have lifestyle issues and we are generally unhealthily. We have expectations for heathcare that are not going to change. We won't tolerate a Canadian system that might make you wai a month to get an MRI Finally, we are the worlds leader in medical innovation and I don't want to see this go away.