Using markets to aggregate information

If you have a wide variety of sources of probabilistic information how do you aggregate it together? From the Microbe World podcast (if you're wondering - yes, I do listen to a regular podcast about microbes!) I learnt that people who need to predict outbreaks of flu have taken an interesting approach to this problem.

Researchers at the University of Iowa have set up an Electronic Market to allow experts in fields to trade on their beliefs. By observing how much people are prepared to bet on various outcomes we can get an aggregated expert opinion of how likely these outcomes are. Apparently they perform fairly well as predictors of the future. And one of these markets is the Influenza Prediction Market where you can buy stock in your favourite influenza strain.

On a related note, the Foresight Exchange has been running for many years now. Click on "claims" and select "Science & Technology:Math" to bet on the likelihood of the Collatz Conjecture or the Riemann Hypothesis.