Based on past elections and economic factors, two professors at the University of Oregon predict that Senator Barack Obama will win the presidential election by a 52 to 48 margin.

In the paper "A Disaggregate Approach to Economic Models of Voting in U.S. Presidential Elections: Forecasts of the 2008 Election," published in the Economics Bulletin, economic professors Stephen Haynes and Joe Stone's research shows that lowest-income states prefer McCain by 55.4 percent to 44.6 percent. Middle income states are almost evenly split between the two candidates and highest-income states prefer Obama by 53.3 percent to 46.65 percent.

Haynes and Stone note in their research that the 52 to 48 margin in favor of Obama falls within the four-point range of statistical error.

Overall the prediction is that Obama and Senator John McCain will be in a statistical dead-heat. But by looking at state income levels, McCain will draw support from lower-income states and Obama will draw higher-income states. Highest income states, like California and New York, have large populations, giving Obama the edge. 

Haynes and Stone used additional factors to address weaknesses in previous estimates of economic voting models. Other models emphasize economic growth, price stability and the role of the political parties. While those models had significant predictive power in most elections, they were unsuccessful in predicting the 1992 and 2004 elections. 

Haynes and Stone found that systematic differences in voting behavior had been ignored, such as voters in higher-income states respond significantly to inflation, change in the Dow-Jones stock market average, the number of terms the incumbent party has held office and national security concerns. Voters in lower-income states respond significantly to economic growth, specifically in job creation and unemployment levels. 

Breaking the states into five groups of 10, ranging from the states with the lowest average income to those with the highest average income, the researchers were able to factor in the additional voting behaviors. 

"The differing views of voters in high-versus low-income states arise, at least in part, by how they are most directly affected by the economy," said Stone. "Voters in high-income states have been affected most by the sharp declines in the stock market, making their views of the incumbent Republican president particularly harsh."