At a few US universities, academics have boiled the art of predicting the winner of the US election down to a dispassionate science.
Some claim their forecasts in presidential elections - typically issued months before Election Day - have been more accurate than opinion polls taken the day before ballots are cast.
Plugging decades of data into spreadsheets, they calculate everything from how much a bad economy is hurting an incumbent to how the results of New Hampshire's presidential primaries, conducted 10 months before an election, can signal who the eventual winner will be.
"What this forecasting really amounts to is quantitative history," said James Campbell of the University at Buffalo.
So far this year, forecasters, in line with many current opinion polls, see Obama squeaking out a victory over Romney.
In a Reuters poll of nine leading forecasters, the median prediction was for Obama to win 50.5% of the vote. However, under the complicated American system, that would not necessarily mean victory because the winner is determined by the state electoral college results.
In 2008, the forecast of the same group, which estimated Obama would receive 52% of the vote as against John McCain's 48%, was about as close to the election results as Gallup's final poll from the last three days of the presidential campaign.
{{/usCountry}}In 2008, the forecast of the same group, which estimated Obama would receive 52% of the vote as against John McCain's 48%, was about as close to the election results as Gallup's final poll from the last three days of the presidential campaign.
{{/usCountry}}