My colleague Don Boudreaux has proposed a clever bet on health care spending with Peter Orszag and Nancy-Ann DeParle:

If the House passes a health-reform bill this year and the Senate
adopts that bill through reconciliation, pick any year in the future
between 2021 and 2046.  Then tell me your official (that is, the
administration’s on-the-record) estimate today of how much Uncle Sam
will spend on health-care that year.  I’ll bet each of you $5,000 that
Uncle Sam’s actual, CPI-adjusted expenditures on health-care in that
year will be at least 25 percent higher than your estimate.

If Uncle Sam’s health-care expenditures in that year are less than
25 percent higher than you project them to be, I’ll congratulate you as
I mail you your checks.  If these expenditures are 25 percent, or more,
higher than you project them to be, I’ll contribute my winnings to a
private health-care charity, as I predict that the need for
philanthropic contributions along those lines will be great.

Notice: If the targets of Boudreaux’s bet weren’t public figures, they could painlessly win $5,000 with certainty.  If they announce that CPI-adjusted expenditures on health-care in 2021 will be one quadrillion dollars – that’s $1,000,000,000,000,000, they’ll win hands down.  But obviously Orszag and DeParle can’t publicly say that.