A note on Intrade probabilities for the control of the House and Senate

For the Senate, Intrade predicts that there is a better than even chance that Republicans will at least get tied control -- that means they are expected to pick up at least 9 seats. As of 5 PM, there is a 43.5 percent probability that Republicans will get 50 seats. There was also a 12.8 percent chance of them getting more than 50 seats. Taken together and adjusting for the fact that the probabilities add up to more than 100 percent, there is a 53.5 percent probability of Republicans picking up at least 9 seats. In the House, there is a 47 percent probability that the Republicans will pick up at least 60 seats and a 69 percent probability of picking up at least 55 seats.