Would Paul Ryan's voucher plan help control medical costs, or drive them further up?

Call it whatever marketing term the right-wing think tank network selects. A voucher system, premium support, saving Medicare. But before we scrap a system that has served America’s seniors well for 46 years, shouldn’t we make sure the cure actually does what it’s purported to do? If a voucher system makes care cost more and not less, it won’t save Medicare. It won’t save the public money at all; it will only switch who is getting the funds from the IRS to a group of private enterprises. It will also mean that fewer seniors will be able to get affordable quality care. So what would a voucher system do? How would it impact long-term costs of delivering healthcare?