CBO misses the mark again

The initial funding for Cash for Clunkers ran out in just one week, and tripling its budget only extended the program until Labor Day. Obviously the government seriously underestimated the demand for nearly free money. Now it appears the same phenomenon has developed for the first-time home buyers tax credit, according to NYTimes.com:

As many as 40 percent of all home buyers this year will qualify for the credit. It is on track to cost the government $15 billion, more than twice the amount that was projected when Congress passed the stimulus bill in February.

These projections were made for very, very narrow programs over a very short time frame, and yet the margin of error was 100% and more. I wonder why anyone thinks the projections on the cost of overhauling health care are any more accurate, for longer time frames and far more complex systems? I sometimes wonder why they even bother with budget projections, they are so far off the mark.

As helpful as the first-time home buyer credit has been, it's not clear that a new floor has been established under home prices yet.