July 26, 2004

Political "futures" markets II

The idea of relying upon futures markets prices to forecast future events has an interesting history. Nearly 20 years ago, Richard Roll published a paper in the American Economic Review entitled "Orange Juice and Weather" which showed, among other things, that the futures market in orange juice concentrate is a better predictor of Florida weather than the National Weather Service. Since the only way one can earn excess profits in a speculative market is to gain an informational advantage over the competition, traders are strongly motivated to try to do just that. As I noted in my previous blog entry about political "futures" markets (see 'Political "futures" markets I'), if markets are informationally efficient, it follows that market prices represent unbiased forecasts concerning future events. Technically, this means that on average, the market's estimate of the average value of the event in question is likely to be quite accurate. Consequently, I believe that political "futures" markets are more reliable indicators of the odds of a Bush or Kerry win than surveys conducted by the various media companies. With this in mind, it is interesting to observe what the political futures markets are telling us. As Alex Tabarrok notes, the market prediction of a Bush victory has hit an all-time low; I just checked the tradesports.com website, and today's closing price for the PRESIDENT.GWBUSH2004 futures contract (George W. Bush is re-elected as United States President) is $49.60, which indicates that the election today is quite literally a tossup (note: since the tradesports contracts pay off $100 if a predefined event occurs and $0 otherwise, the reported price is essentially a probability measure). However, it does appear that regardless of which party wins the presidential election, the House and Senate will most likely have Republican majorities. This is evident because today's closing price for the SENATE.GOP.2004 futures contract (Republicans maintain control of the US Senate in 2004 Election) is $76.50, whereas today's closing price for the HOUSE.GOP.2004 futures contract (Republicans maintain control of the House in 2004 Election) is $87.

Posted by Jim Garven at July 26, 2004 03:08 PM