I felt bad for talking about prediction markets that don't require you to put up real money, so I decided to check out one that does. It's called Intrade, and it operates out of Ireland, because nobody is sure if this kind of market is legal in the U.S.
Which, BTW, is dumb, because the stock market and futures markets are also gambling. A few years ago I came across a guy who was trying to start a prediction market in the U.S. He had apparently convinced the proper authorities that what he was doing is legal, but was having trouble finding investors to back him. I believe he got it started, but I don't know where it is now.
On Intrade, Obama is currently favored to win the presidency. His stock is trading at 64.6, meaning there's a 64.6 percent chance he will win, in current opinion. McCain is at 30.4 percent.
(Comparisons: The NewsFutures market puts the odds of a Democrat winning the election at 65 percent. The Foresight Exchange predicts a Dem win at 66.)
California passing the stupid constitutional amendment to ban same-sex marriage is at 52.5, up from 50 soon after it started trading on June 7, but down from a peak of 65 on June 27.
Shares of Osama bin Laden being captured by September 30 are just 5.0, but buyers saying he'll be captured by next March 31 are putting the odds at 20 percent.
The odds of someone winning Google's Lunar X prize are currently 25 percent, down from a peak of 80 percent a few months ago.
Intrade also points to a YouTube video of an ABC TV report on its trading system. It's interesting.