Of course, they will use the methods that you have outlined to try to restrain costs, but history teaches us that it will not be possible:
In fact, every federal social program has cost far more than originally predicted. For instance, in 1967 the House Ways and Means Committee predicted that Medicare would cost $12 billion in 1990, a staggering $95 billion underestimate. Medicare first exceeded $12 billion in 1975. In 1965 federal actuaries figured the Medicare hospital program would end up running $9 billion in 1990. The cost was more than $66 billion.
In 1987 Congress estimated that the Medicaid Special Hospitals Subsidy would hit $100 million in 1992. The actual bill came to $11 billion. The initial costs of Medicare's kidney-dialysis program, passed in 1972, were more than twice projected levels.
The Congressional Budget Office doubled the estimated cost of Medicare's catastrophic insurance benefit subsequently repealed from $5.7 billion to $11.8 billion annually within the first year of its passage. The agency increased the projected cost of the skilled nursing benefit an astonishing sevenfold over roughly the same time frame, from $2.1 billion to $13.5 billion. And in 1935 a naive Congress predicted $3.5 billion in Social Security outlays in 1980, one-thirtieth the actual level of $105 billion.
Doug Bandow on Medicare on National Review Online
