Prediction Markets Update (September 21, 2008)

The 2008.PRES.OBAMA Intrade contract now trades at 50.2 , whereas the 2008.PRES.McCAIN Intrade contract is currently trading at 47.8 (compared with 50.8 and 46.1 respectively as reported on yesterday’s update).

The state-by-state contracts continue to imply that Mr. Obama currently holds a 273-227 “lead” over Mr. McCain (based upon my cutoff price point of 55 for allocating Electoral College votes). The “swing” states continue to include Nevada (5 Electoral College votes), Ohio (20 Electoral College votes), and Virginia (13 Electoral College votes).

FiveThirtyEight.com currently gives Mr. Obama a 311.5 to 226.5 advantage over Mr. McCain. If the three swing states (Nevada, Ohio, and Virginia) went for Obama and all of the remaining states allocated themselves according to the manner described in the addendum below, this would result in a 311 to 227 Electoral College advantage for Mr. Obama.

Addendum: September 21, 2008 Electoral College Vote allocation

Barack Obama (273): California (55), Colorado (9), Connecticut (7), Delaware (3), District of Columbia (3), Hawaii (4), Illinois (21), Iowa (7), Maine (4), Maryland (10), Massachusetts (12), Michigan (17), Minnesota (10), New Hampshire (4), New Jersey (15), New Mexico (5), New York (31), Oregon (7), Pennsylvania (21), Rhode Island (4), Vermont (3), Washington (11), and Wisconsin (10)

John McCain (227): Alabama (9), Alaska (3), Arizona (10), Arkansas (6), Florida (27), Georgia (15), Idaho (4), Indiana (11), Kansas (6), Kentucky (8), Louisiana (9), Mississippi (6), Missouri (11), Montana (3), Nebraska (5), North Carolina (15), North Dakota (3), Oklahoma (7), South Carolina (8), South Dakota (3), Tennessee (11), Texas (34), Utah (5), West Virginia (5), and Wyoming (3)