Now that final election vote tallies are in, here's a chart plotting pre-election Tradesports prices (X-axis) vs. the actual Bush-Kerry margin (Y-axis) for each state. Margins were calculated as if it were a two-man race, i.e., ignoring third-party candidates. Prices (theoretically a gauge of probability) are based on an exponentially weighted average of data snapshots from Tradesports taken between Saturday, October 30th, and Election Day - Tuesday, November 2nd. E-mail me if you want the raw data (>1MB spreadsheet). Note: R-squared value = 0.77!
(click for a larger image)